Leonardo SORCI

Pubblicazioni

Leonardo SORCI

 

68 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
45 1 Contributo su Rivista
15 4 Contributo in Atti di Convegno (Proceeding)
7 5 Altro
1 2 Contributo in Volume
Anno
Risorse
2023
Properly Substituted Benzimidazoles as a New Promising Class of Nicotinate Phosphoribosyltransferase (NAPRT) Modulators
PHARMACEUTICALS
Autore/i: Baldassarri, C; Giorgioni, G; Piergentili, A; Quaglia, W; Fontana, S; Mammoli, V; Minazzato, G; Marangoni, E; Gasparrini, M; Sorci, L; Raffaelli, N; Cappellacci, L; Petrelli, R; Del Bello, F
Classificazione: 1 Contributo su Rivista
Abstract: The prevention of nicotinamide adenine dinucleotide (NAD) biosynthesis is considered an attractive therapeutic approach against cancer, considering that tumor cells are characterized by an increased need for NAD to fuel their reprogrammed metabolism. On the other hand, the decline of NAD is a hallmark of some pathological conditions, including neurodegeneration and metabolic diseases, and boosting NAD biosynthesis has proven to be of therapeutic relevance. Therefore, targeting the enzymes nicotinamide phosphoribosyltransferase (NAMPT) and nicotinate phosphoribosyltransferase (NAPRT), which regulate NAD biosynthesis from nicotinamide (NAM) and nicotinic acid (NA), respectively, is considered a promising strategy to modulate intracellular NAD pool. While potent NAMPT inhibitors and activators have been developed, the search for NAPRT modulators is still in its infancy. In this work, we report on the identification of a new class of NAPRT modulators bearing the 1,2-dimethylbenzimidazole scaffold properly substituted in position 5. In particular, compounds 24, 31, and 32 emerged as the first NAPRT activators reported so far, while 18 behaved as a noncompetitive inhibitor toward NA (K-i = 338 mu M) and a mixed inhibitor toward phosphoribosyl pyrophosphate (PRPP) (K-i = 134 mu M). From in vitro pharmacokinetic studies, compound 18 showed an overall good ADME profile. To rationalize the obtained results, docking studies were performed on the NAPRT structure. Moreover, a preliminary pharmacophore model was built to shed light on the shift from inhibitors to activators.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/313849 Collegamento a IRIS

2023
A Versatile Continuous Fluorometric Enzymatic Assay for Targeting Nicotinate Phosphoribosyltransferase
MOLECULES
Autore/i: Minazzato, G.; Marangoni, E.; Fortunato, C.; Petrelli, R.; Cappellacci, L.; Del Bello, F.; Sorci, L.; Gasparrini, M.; Piacente, F.; Bruzzone, S.; Raffaelli, N.
Classificazione: 1 Contributo su Rivista
Abstract: The maintenance of a proper NAD+ pool is essential for cell survival, and tumor cells are particularly sensitive to changes in coenzyme levels. In this view, the inhibition of NAD+ biosynthesis is considered a promising therapeutic approach. Current research is mostly focused on targeting the enzymes nicotinamide phosphoribosyltransferase (NAMPT) and nicotinate phosphoribosyltransferase (NAPRT), which regulate NAD+ biosynthesis from nicotinamide and nicotinic acid, respectively. In several types of cancer cells, both enzymes are relevant for NAD+ biosynthesis, with NAPRT being responsible for cell resistance to NAMPT inhibition. While potent NAMPT inhibitors have been developed, only a few weak NAPRT inhibitors have been identified so far, essentially due to the lack of an easy and fast screening assay. Here we present a continuous coupled fluorometric assay whereby the product of the NAPRT-catalyzed reaction is enzymatically converted to NADH, and NADH formation is measured fluorometrically. The assay can be adapted to screen compounds that interfere with NADH excitation and emission wavelengths by coupling NADH formation to the cycling reduction of resazurin to resorufin, which is monitored at longer wavelengths. The assay system was validated by confirming the inhibitory effect of some NA-related compounds on purified human recombinant NAPRT. In particular, 2-hydroxynicotinic acid, 2-amminonicotinic acid, 2-fluoronicotinic acid, pyrazine-2-carboxylic acid, and salicylic acid were confirmed as NAPRT inhibitors, with Ki ranging from 149 to 348 µM. Both 2-hydroxynicotinic acid and pyrazine-2-carboxylic acid were found to sensitize OVCAR-5 cells to the NAMPT inhibitor FK866 by decreasing viability and intracellular NAD+ levels.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/313831 Collegamento a IRIS

2022
The interaction between human NAMPT and NAPRT with TLR4: a focus on the molecular determinants
PROTEINE 2022
Autore/i: Gasparrini, M; Sorci, L; Mazzola, F; Cuccioloni, M; Angeletti, M; Deaglio, S; Audrito, V; Raffaelli, N
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/305761 Collegamento a IRIS

2022
Human extracellular NAMPT and NAPRT mediate the inflammatory response through TLR4-binding: molecular insights into the mechanism of interaction
the 4th ISFMS—Biochemistry, Molecular Biology and Druggability of Proteins
Autore/i: Gasparrini, Massimiliano; Sorci, Leonardo; Mazzola, Francesca; Cuccioloni, Massimiliano; Angeletti, Mauro; Deaglio, Silvia; Audrito, Valentina; Raffaelli, Nadia
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/305841 Collegamento a IRIS

2022
Bacterial NadQ (COG4111) is a Nudix-like, ATP-responsive regulator of NAD biosynthesis
JOURNAL OF STRUCTURAL BIOLOGY
Autore/i: Minazzato, Gabriele; Gasparrini, Massimiliano; Heroux, Annie; Sernova, Natalia V; Rodionov, Dmitry A; Cianci, Michele; Sorci, Leonardo; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Abstract: Nicotinamide-adenine dinucleotide (NAD) is centrally important to metabolic reactions that involve redox chemistry. In bacteria, NAD biosynthesis is controlled by different transcription factors, depending on the spe-cies. Among the four regulators identified so far, the protein NadQ is reported to act as a repressor of the de novo NAD biosynthetic pathway in proteobacteria. Using comparative genomics, a systematic reconstruction of NadQ regulons in thousands of fully sequenced bacterial genomes has been performed, confirming that NadQ is present in alpha-proteobacteria and some beta- and gamma-proteobacteria, including pathogens like Bordetella pertussis and Neisseria meningitidis, where it likely controls de novo NAD biosynthesis. Through mobility shift assay and mutagenesis, the DNA binding activity of NadQ from Agrobacterium tumefaciens was experimentally validated and determined to be suppressed by ATP. The crystal structures of NadQ in native form and in complex with ATP were determined, indicating that NadQ is a dimer, with each monomer composed of an N-terminal Nudix domain hosting the effector binding site and a C-terminal winged helix-turn-helix domain that binds DNA. Within the dimer, we found one ATP molecule bound, at saturating concentration of the ligand, in keeping with an intrinsic asymmetry of the quaternary structure. Overall, this study provided the basis for depicting a working model of NadQ regulation mechanism.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/314092 Collegamento a IRIS

2022
Mechanistic insight toward EGFR activation induced by ATP: role of mutations and water in ATP binding patterns
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
Autore/i: Laudadio, Emiliano; Mobbili, Giovanna; Sorci, Leonardo; Galeazzi, Roberta; Minnelli, Cristina
Classificazione: 1 Contributo su Rivista
Abstract: The discovery of mutations within the kinase domain of the epidermal growth factor receptor (EGFR) gene has enabled a new era of targeted therapy in non-small cell lung cancer (NSCLC). Drugs belonging to the family of tyrosine kinase inhibitors (TKIs) are designed to bind ATP binding cleft, anyway, the occurrence of aminoacidic mutations decreases the effectiveness of the antitumoral treatment. Despite many efforts has been already made, the impact of the mutations on conformation and stability of EGFR-ATP complexes is still not fully understood. Therefore, we investigated the effect of mutations that leads to changes in Michaelis-Menten constant (Km) using dynamic docking simulations. We focused on six different EGFR forms in relation to different mutation states, then we found a good correlation between the calculated ATP affinities and Km values. Moreover, since dynamic switching of TKEGFR from the inactive towards the active state is known to regulate the kinase activity, we observed that ATP induces the inwards movement of the aC-helix with the Lys745 close to Glu762 in all cases. This means that ATP binding should be the first step in promoting the conformational shift to the active state. Finally, we highlighted for the first time the key contribution of water hydrogen bond and water-bridge networks in the modulation of ATP affinity. The identified mutant-specific ATP binding patterns and conformational features could be much useful to guide cancer therapy and develop more personalized medicine.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306582 Collegamento a IRIS

2022
Molecular insights into the interaction between human nicotinamide phosphoribosyltransferase and Toll-like receptor 4
THE JOURNAL OF BIOLOGICAL CHEMISTRY
Autore/i: Gasparrini, M.; Mazzola, F.; Cuccioloni, M.; Sorci, L.; Audrito, V.; Zamporlini, F.; Fortunato, C.; Amici, A.; Cianci, M.; Deaglio, S.; Angeletti, M.; Raffaelli, N.
Classificazione: 1 Contributo su Rivista
Abstract: The secreted form of the enzyme nicotinamide phosphoribosyltransferase (NAMPT), which catalyzes a key reaction in intracellular NAD biosynthesis, acts as a damage-associated molecular pattern triggering Toll-like receptor 4 (TLR4)mediated inflammatory responses. However, the precise mechanism of interaction is unclear. Using an integrated approach combining bioinformatics and functional and structural analyses, we investigated the interaction between NAMPT and TLR4 at the molecular level. Starting from previous evidence that the bacterial ortholog of NAMPT cannot elicit the inflammatory response, despite a high degree of structural conservation, two positively charged areas unique to the human enzyme (the α1-α2 and β1-β2 loops) were identified as likely candidates for TLR4 binding. However, alanine substitution of the positively charged residues within these loops did not affect either the oligomeric state or the catalytic efficiency of the enzyme. The kinetics of the binding of wildtype and mutated NAMPT to biosensor-tethered TLR4 was analyzed. We found that mutations in the α1-α2 loop strongly decreased the association rate, increasing the KD value from 18 nM, as determined for the wildtype, to 1.3 μM. In addition, mutations in the β1-β2 loop or its deletion increased the dissociation rate, yielding KD values of 0.63 and 0.22 μM, respectively. Mutations also impaired the ability of NAMPT to trigger the NF-κB inflammatory signaling pathway in human cultured macrophages. Finally, the involvement of the two loops in receptor binding was supported by NAMPT-TLR4 docking simulations. This study paves the way for future development of compounds that selectively target eNAMPT/TLR4 signaling in inflammatory disorders.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298389 Collegamento a IRIS

2022
Identification of a novel nitroflavone-based scaffold for designing mutant-selective EGFR tyrosine kinase inhibitors targeting T790M and C797S resistance in advanced NSCLC
BIOORGANIC CHEMISTRY
Autore/i: Minnelli, Cristina; Laudadio, Emiliano; Sorci, Leonardo; Sabbatini, Giulia; Galeazzi, Roberta; Amici, Adolfo; Semrau, Marta S.; Storici, Paola; Rinaldi, Samuele; Stipa, Pierluigi; Marcaccio, Massimo; Mobbili, Giovanna
Classificazione: 1 Contributo su Rivista
Abstract: The inhibition of the Epidermal Growth Factor (EGFR) represents one of the most promising strategies in non small cell lung cancer (NSCLC) therapy. The recently identified C797S mutation causes resistance of EGFRL858R/T790M against osimertinib, the latest approved third generation EGFR inhibitor. The identification of small molecules capable of selectively inhibiting the T790M mutations also in the late-onset C797S mutation is a desirable strategy and novel chemical structures might provide new insight in the overcoming resistance mechanisms. Here we report the identification of a novel mutant-selective privileged molecular core; guided by a structure-based drug design, a flavone skeleton has been rationally modified, and a virtual library generated. Reversible EGFR inhibitors targeting both L858R/T790M and L858R/T790M/C797S mutations with a higher affinity with respect to the wild type one are discovered via a three-track virtual screening. Selected hits were synthesized and tested in an activity-based enzyme assay against wild-type EGFR, L858R/T790M, as well as L858R/T790M/C797S. The results showed that a nitroflavone-based compound inhibits the phosphorylation of EGFR mutants at low-micromolar concentration showing selectivity over the wild type ones. Structurally similar flavone analogues have been synthesized and the following inhibition assays underlied the importance of both the presence and position of the nitrophenoxy moiety.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/308602 Collegamento a IRIS

2021
Structural requirements for the interaction of the enzyme nicotinamide phosphoribosyltransferase with Toll-like receptor 4
FEBS openbio
Autore/i: Gasparrini, Massimiliano; Mazzola, Francesca; Fortunato, Carlo; Zamporlini, Federica; Sorci, Leonardo; Audrito, Valentina; Deaglio, Silvia; Cuccioloni, Massimiliano; Angeletti, Mauro; Raffaelli, Nadia
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/305760 Collegamento a IRIS

2021
The Prospective Synergy of Antitubercular Drugs With NAD Biosynthesis Inhibitors
FRONTIERS IN MICROBIOLOGY
Autore/i: Rohde, K. H.; Sorci, L.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/288299 Collegamento a IRIS

2021
Enzymology of extracellular NAD metabolism
CELLULAR AND MOLECULAR LIFE SCIENCES
Autore/i: Gasparrini, M.; Sorci, L.; Raffaelli, N.
Classificazione: 1 Contributo su Rivista
Abstract: Extracellular NAD represents a key signaling molecule in different physiological and pathological conditions. It exerts such function both directly, through the activation of specific purinergic receptors, or indirectly, serving as substrate of ectoenzymes, such as CD73, nucleotide pyrophosphatase/phosphodiesterase 1, CD38 and its paralog CD157, and ecto ADP ribosyltransferases. By hydrolyzing NAD, these enzymes dictate extracellular NAD availability, thus regulating its direct signaling role. In addition, they can generate from NAD smaller signaling molecules, like the immunomodulator adenosine, or they can use NAD to ADP-ribosylate various extracellular proteins and membrane receptors, with significant impact on the control of immunity, inflammatory response, tumorigenesis, and other diseases. Besides, they release from NAD several pyridine metabolites that can be taken up by the cell for the intracellular regeneration of NAD itself. The extracellular environment also hosts nicotinamide phosphoribosyltransferase and nicotinic acid phosphoribosyltransferase, which inside the cell catalyze key reactions in NAD salvaging pathways. The extracellular forms of these enzymes behave as cytokines, with pro-inflammatory functions. This review summarizes the current knowledge on the extracellular NAD metabolome and describes the major biochemical properties of the enzymes involved in extracellular NAD metabolism, focusing on the contribution of their catalytic activities to the biological function. By uncovering the controversies and gaps in their characterization, further research directions are suggested, also to better exploit the great potential of these enzymes as therapeutic targets in various human diseases.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/290751 Collegamento a IRIS

2020
Small extracellular vesicles deliver miR-21 and miR-217 as pro-senescence effectors to endothelial cells
JOURNAL OF EXTRACELLULAR VESICLES
Autore/i: Mensa, E.; Guescini, M.; Giuliani, A.; Bacalini, M. G.; Ramini, D.; Corleone, G.; Ferracin, M.; Fulgenzi, G.; Graciotti, L.; Prattichizzo, F.; Sorci, L.; Battistelli, M.; Monsurro, V.; Bonfigli, A. R.; Cardelli, M.; Recchioni, R.; Marcheselli, F.; Latini, S.; Maggio, S.; Fanelli, M.; Amatori, S.; Storci, G.; Ceriello, A.; Stocchi, V.; De Luca, M.; Magnani, L.; Rippo, M. R.; Procopio, A. D.; Sala, C.; Budimir, I.; Bassi, C.; Negrini, M.; Garagnani, P.; Franceschi, C.; Sabbatinelli, J.; Bonafe, M.; Olivieri, F.
Classificazione: 1 Contributo su Rivista
Abstract: The role of epigenetics in endothelial cell senescence is a cutting-edge topic in ageing research. However, little is known of the relative contribution to pro-senescence signal propagation provided by microRNAs shuttled by extracellular vesicles (EVs) released from senescent cells. Analysis of microRNA and DNA methylation profiles in non-senescent (control) and senescent (SEN) human umbilical vein endothelial cells (HUVECs), and microRNA profiling of their cognate small EVs (sEVs) and large EVs demonstrated that SEN cells released a significantly greater sEV number than control cells. sEVs were enriched in miR-21-5p and miR-217, which target DNMT1 and SIRT1. Treatment of control cells with SEN sEVs induced a miR-21/miR-217-related impairment of DNMT1-SIRT1 expression, the reduction of proliferation markers, the acquisition of a senescent phenotype and a partial demethylation of the locus encoding for miR-21. MicroRNA profiling of sEVs from plasma of healthy subjects aged 40–100 years showed an inverse U-shaped age-related trend for miR-21-5p, consistent with senescence-associated biomarker profiles. Our findings suggest that miR-21-5p/miR-217 carried by SEN sEVs spread pro-senescence signals, affecting DNA methylation and cell replication.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/275020 Collegamento a IRIS

2020
Functional characterization of COG1713 (YqeK) as a novel diadenosine tetraphosphate hydrolase family
JOURNAL OF BACTERIOLOGY
Autore/i: Minazzato, Gabriele; Gasparrini, Massimiliano; Amici, Adolfo; Cianci, Michele; Mazzola, Francesca; Orsomando, Giuseppe; Sorci, Leonardo; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Abstract: Diadenosine tetraphosphate (Ap4A) is a dinucleotide found in both prokaryotes and eukaryotes. In bacteria, its cellular level increases following exposure to various stress signals and stimuli, and its accumulation is generally correlated to increased sensitivity to the stressful condition, decreased pathogenicity, and enhanced antibiotic susceptibility. Ap4A is produced as a byproduct of tRNA aminoacylation, and it is cleaved to ADP molecules by hydrolases of the ApaH and Nudix families and/or by specific phosphorylases. Here, starting from the evidence that the recombinant protein YqeK from Staphylococcus aureus copurified with ADP, and aided by thermal shift and kinetic analyses, we identified the YqeK family of proteins (COG1713) as an unprecedented class of symmetrically-cleaving Ap4A hydrolases. We validated the functional assignment by confirming YqeK ability to affect the in vivo level of Ap4A in B. subtilis YqeK shows a catalytic efficiency towards Ap4A similar to that of the symmetrically-cleaving Ap4A hydrolases of the known ApaH family, although it displays a distinct fold, typical of proteins of the HD domain superfamily that harbor a diiron cluster. Analysis of the available 3D structures of three members of the YqeK family provided hints on substrate binding mode. Phylogenetic analysis revealed the occurrence of YqeK proteins in a consistent group of Gram-positive bacteria that lack ApaH enzymes. Comparative genomics highlighted that yqeK and apaH genes share a similar genomic context, being frequently found in operons involved in an integrated response to stress signals.IMPORTANCEElevation of Ap4A level in bacteria is associated with increased sensitivity to heat and oxidative stress, reduced antibiotic tolerance, and decreased pathogenicity. ApaH is the major Ap4A hydrolase in γ- and β- proteobacteria, and it has been recently proposed as a novel target to weaken the bacterial resistance to antibiotics. Here, we identified the orphan YqeK protein family (COG1713) as a highly efficient Ap4A hydrolase family, with members distributed in a consistent group of bacterial species that lack the ApaH enzyme. Among them are the pathogens Staphylococcus aureus, Streptococcus pneumoniae, and Mycoplasma pneumoniae By identifying the player contributing to Ap4A homeostasis in these bacteria, we disclose a novel target to develop innovative antibacterial strategies.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/275473 Collegamento a IRIS

2020
Inhibition of the NAD salvage pathway in schistosomes impairs metabolism, reproduction, and parasite survival
PLOS PATHOGENS
Autore/i: Schultz, M. D.; Dadali, T.; Jacques, S. A.; Muller-Steffner, H.; Foote, J. B.; Sorci, L.; Kellenberger, E.; Botta, D.; Lund, F. E.
Classificazione: 1 Contributo su Rivista
Abstract: NAD, a key co-enzyme required for cell metabolism, is synthesized via two pathways in most organisms. Since schistosomes apparently lack enzymes required for de novo NAD biosynthesis, we evaluated whether these parasites, which infect >200 million people worldwide, maintain NAD homeostasis via the NAD salvage biosynthetic pathway. We found that intracellular NAD levels decline in schistosomes treated with drugs that block production of nicotinamide or nicotinamide mononucleotide–known NAD precursors in the non-deamidating salvage pathway. Moreover, in vitro inhibition of the NAD salvage pathway in schistosomes impaired egg production, disrupted the outer membranes of both immature and mature parasites and caused loss of mobility and death. Inhibiting the NAD salvage pathway in schistosome-infected mice significantly decreased NAD levels in adult parasites, which correlated with reduced egg production, fewer liver granulomas and parasite death. Thus, schistosomes, unlike their mammalian hosts, appear limited to one metabolic pathway to maintain NAD-dependent metabolic processes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/283981 Collegamento a IRIS

2019
A circulating NAD biosynthetic enzyme is a novel modulator of inflammation
JOURNAL OF IMMUNOLOGY
Autore/i: Manago’, Antonella; Audrito, Valentina; Mazzola, Francesca; Sorci, Leonardo; Gaudino, Federica; Gizzi, Katiuscia; Incarnato, Danny; Minazzato, Gabriele; Ianniello, Alice; Varriale, Antonio; D’Auria, Sabato; Mengozzi, Giulio; Politano, Gianfranco; Oliviero, Salvatore; Raffaelli, Nadia; Silvia Deaglio, And
Classificazione: 1 Contributo su Rivista
Abstract: Damage-associated molecular patterns (DAMPs) are molecules that can be actively or passively released by injured tissues and that activate the immune system. Here we show for the first time that the NAD biosynthetic enzyme nicotinate phosphoribosyltransferase (NAPRT), the rate-limiting enzymes in the intracellular synthesis of NAD from nicotinic acid, is physiologically present in human sera, where it acts as a novel DAMP. We detected NAPRT in plasma/sera from human donors by antibody-mediated luminex assays and mass spectrometry. Exposure of human and mouse macrophages to NAPRT triggers activation of ERK1/2, phosphorylation of IKKα/β and nuclear translocation of the p65 subunit of the NF-kB complex, with synthesis and secretion of inflammatory cytokines, including IL-1β, IL-8, TNFα and CCL3. Furthermore, NAPRT enhances monocyte differentiation into macrophages, by inducing macrophage colony-stimulating factor. These effects are independent of the NAPRT catalytic activity, but rely on the protein’s binding to TLR4, as demonstrated by showing direct in vitro interaction and by the in vivo lack of NAPRT effects in TLR4−/− macrophages. In line with the finding that NAPRT mediates endotoxin tolerance, sera from patients with sepsis or septic shock contain the highest levels of circulating NAPRT, compared to other chronic inflammatory conditions, including cancer. Importantly, patients with serum NAPRT >15 ng/ml are characterized by a worse clinical outcome, compared to the counterparts. Together, these data identify NAPRT as a novel endogenous ligand for TLR4 and a critical mediator of inflammation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/278497 Collegamento a IRIS

2019
Novel Antimycobacterial Compounds Suppress NAD Biogenesis by Targeting a Unique Pocket of NaMN Adenylyltransferase
ACS CHEMICAL BIOLOGY
Autore/i: Osterman, Andrei L.; Rodionova, Irina; Li, Xiaoqing; Sergienko, Eduard; Ma, Chen-Ting; Catanzaro, Antonino; Pettigrove, Mark E.; Reed, Robert W.; Gupta, Rashmi; Rohde, Kyle H.; Korotkov, Konstantin V.; Sorci, Leonardo
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266889 Collegamento a IRIS

2019
NAD-Biosynthetic and Consuming Enzymes as Central Players of Metabolic Regulation of Innate and Adaptive Immune Responses in Cancer
FRONTIERS IN IMMUNOLOGY
Autore/i: Audrito, Valentina; Managò, Antonella; Gaudino, Federica; Sorci, Leonardo; Messana, Vincenzo Gianluca; Raffaelli, Nadia; Deaglio, Silvia
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269455 Collegamento a IRIS

2019
Extracellular nicotinate phosphoribosyltransferase binds Toll like receptor 4 and mediates inflammation
NATURE COMMUNICATIONS
Autore/i: Manago, A.; Audrito, V.; Mazzola, F.; Sorci, L.; Gaudino, F.; Gizzi, K.; Vitale, N.; Incarnato, D.; Minazzato, G.; Ianniello, A.; Varriale, A.; D'Auria, S.; Mengozzi, G.; Politano, G.; Oliviero, S.; Raffaelli, N.; Deaglio, S.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269994 Collegamento a IRIS

2018
Exosome and microvesicle miRNAs belong to the pro-inflammatory secretome of senescent endothelial cells
Aging and Metabolism
Autore/i: Mensa, E; Guescini, M; Sorci, L; Ferracin, M; Monsurrò, V; Fulgenzi, G; Graciotti, L; Storci, G; Giuliani, Alessandro; Prattichizzo, F; Garagnani, P; Rippo, Mr; Bonafé, M and Olivieri F
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266407 Collegamento a IRIS

2018
Mycobacterial tuberculosis NadD, a promise for targeting latent and drug-resistant tuberculosis
Targeting Phage Therapy & Antibiotic Resistance - Phage therapy and other innovative ideas
Autore/i: Sorci, Leonardo
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266408 Collegamento a IRIS

2017
Synthesis and degradation of adenosine 5’-tetraphosphate by Nicotinamide and Nicotinate phosphoribosyltransferases
CELL CHEMICAL BIOLOGY
Autore/i: Amici, Adolfo; Grolla, Ambra A.; Del Grosso, Erika; Bellini, Roberta; Bianchi, Michele; Travelli, Cristina; Garavaglia, Silvia; Sorci, Leonardo; Raffaelli, Nadia; Ruggieri, Silverio; Genazzani, Armando A.; Orsomando, Giuseppe
Classificazione: 1 Contributo su Rivista
Abstract: Adenosine 5'-tetraphosphate (Ap4) is a ubiquitous metabolite involved in cell signaling in mammals. Its full physiological significance remains unknown. Here we show that two enzymes committed to NAD biosynthesis, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinate phosphoribosyltransferase (NAPT), can both catalyze the synthesis and degradation of Ap4 through their facultative ATPase activity. We propose a mechanism for this unforeseen additional reaction, and demonstrate its evolutionary conservation in bacterial orthologs of mammalian NAMPT and NAPT. Furthermore, evolutionary distant forms of NAMPT were inhibited in vitro by the FK866 drug but, remarkably, it does not block synthesis of Ap4. In fact, FK866-treated murine cells showed decreased NAD but increased Ap4 levels. Finally, murine cells and plasma with engineered or naturally fluctuating NAMPT levels showed matching Ap4 fluctuations. These results suggest a role of Ap4 in the actions of NAMPT, and prompt to evaluate the role of Ap4 production in the actions of NAMPT inhibitors.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/241271 Collegamento a IRIS

2016
Bioinformatics and comparative genomics unveil an evolutionary conserved phage NAD metabolism
3rd NorHGT & LUCA (Network of Researchers on Horizontal Gene Transfer & Last Universal Cellular Ancestor) conference: the landscape of emergence of life
Autore/i: Sorci, Leonardo
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Bacteriophages, in addition to genes essential for their own propagation, can harbor a second class of genes which are not directly implicated in the viral infection and replication. Although there is a general consensus that these genes confer selective advantage to viruses, there is a paucity of information on their possible function. Thus, more evidence is needed to support this paradigm. Enormous advances have been made in phage genomics in the last few years, offering novel opportunities to tackle this problem with bioinformatics approaches. Using comparative genome analysis performed on nearly two thousand complete phage genomes currently available, we identified a group of nearly fifty phages encoding their own biosynthesis pathways to the essential NAD cofactor from the vitamin precursors nicotinamide (Nm) and nicotinamide riboside (NmR). This viral NAD synthesis is distinct from the bacterial host NAD biosynthesis which is supported by a different set of genes. A comprehensive genomic reconstruction of phage-encoded NAD metabolism, which included NAD-consuming activities, identified three distinct metabolic variants capable of i) synthesizing and consuming NAD, ii) consuming NAD, or iii) synthesizing nicotinamide mononucleotide, a rare NAD metabolic intermediate in bacteria. We propose that these variants reflect different strategies contributing to subvert the machinery of the host cell. Finally, a phylogenetic analysis of the phage NAD biosynthetic shunt revealed a complex evolutionary scenario dominated by cross-kingdom gene transfer events. Notably, these phages assembled their own NAD pathway by acquiring and possibly modifying functionally related genes from host cells, but also contributed to spread these functional roles across a diverse group of bacteria. This case may be a relevant, and yet undisclosed example of how viruses contributed to fine-tune metabolic processes in the early evolutionary history of life.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/247686 Collegamento a IRIS

2016
Biological Activities of the Essential Oil from Erigeron floribundus
MOLECULES
Autore/i: Petrelli, Riccardo; Orsomando, Giuseppe; Sorci, Leonardo; Maggi, Filippo; Ranjbarian, Farahnaz; Biapa Nya, Prosper C; Petrelli, Dezemona; Vitali, Luca A; Lupidi, Giulio; Quassinti, Luana; Bramucci, Massimo; Hofer, Anders; Cappellacci, Loredana
Classificazione: 1 Contributo su Rivista
Abstract: Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (inhibition zone diameter, IZD of 14 mm, minimum inhibitory concentration, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (tocopherol-equivalent antioxidant capacity, TEAC = 411.9 μmol·TE/g).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236818 Collegamento a IRIS

2016
Regulation of host immune responses to Schistosoma mansoni by the inhibition of the parasitic NAD salvage pathway
JOURNAL OF IMMUNOLOGY
Autore/i: Schultz, Michael D; Dadali, Tulin; Botta, Davide; Manouvakhova, Anna; Sosa, Melinda; Mckellip, Sara N; Woods, Lakeisha; Tower, Nichole A; Ross, Larry J; Rasmussen, Lynn; White, Lucile; Padmalayam, Indira; Augelli Szafran, Corinne; Everts, Maaike; Sorci, Leonardo; Bostwick, James; Suto, Mark J; Lund, Frances E.
Classificazione: 1 Contributo su Rivista
Abstract: T regulatory cells (Tregs) are a subset of FoxP3+ lymphocytes that maintain immune homeostasis through immunosuppressive signaling. In many helminth infections, one mechanism of immune evasion involves the influx and maintenance of Tregs. Multiple mechanisms can control Treg homeostasis including a Nicotinamide adenine dinucleotide (NAD) dependent apoptotic pathway. In most organisms, the two pathways of NAD synthesis include de novo synthesis from amino acid precursors, and the salvage pathway in which nicotinamide-containing precursors are recycled into NAD. A comparative genome analysis of S. mansoni, the parasite that causes Schistosomiasis, enabled the assembly of a putative NAD biosynthetic pathway. Only orthologues of NAD salvage-specific genes were identified and expression was confirmed by PCR. This suggests that S. mansoni decreases host NAD levels in a salvage-specific manner and rescues Tregs from NAD-dependent cell death. As such, we hypothesized that inhibition of NAD biosynthesis through the salvage pathway would result in impaired NAD uptake by S. mansoni and restoration of NAD-mediated cell death of Tregs. Indeed, co-culture with S. mansoni prevented NAD-induced toxicity and death of Tregs. Blockade of the NAD salvage pathway via the inhibition of Schistosoma mansoni NAD catabolizing enzyme (SmNACE) restored NAD-mediated cell death of Tregs. Furthermore, SmNACE inhibition decreased intracellular NAD levels and reduced metabolism and viability of the parasite. Collectively, our data suggest that inhibition of NAD biosynthesis blocks immune evasion and metabolism of S. mansoni, and that targeting the NAD salvage pathway is a promising therapeutic approach for the treatment of Schistosomiasis.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/247688 Collegamento a IRIS

2016
Evolutionary and Comparative Genome Analysis of Phage NAD Metabolic Genes
THE FASEB JOURNAL
Autore/i: Sorci, Leonardo; Kazanov, Marat D; Gerdes, Svetlana
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/247696 Collegamento a IRIS

2016
Diverse biological effects of the essential oil from Iranian Trachyspermum ammi
ARABIAN JOURNAL OF CHEMISTRY
Autore/i: Vitali, Luca A; Beghelli, Daniela; Biapa Nya, Prosper C.; Bistoni, Onelia; Cappellacci, Loredana; Damiano, Silvia; Lupidi, Giulio; Maggi, Filippo; Orsomando, Giuseppe; Papa, Fabrizio; Petrelli, Dezemona; Petrelli, Riccardo; Quassinti, Luana; Sorci, Leonardo; Zadeh, Majid Majd; Bramucci, Massimo
Classificazione: 1 Contributo su Rivista
Abstract: Trachyspermum ammi (Apiaceae) is a plant with a good reputation in the traditional Persian and Ayurvedic medicine. The hydrodistilled essential oil from the fruits of T. ammi, known as 'ajwain oil', is used in countries such as Iraq, Iran, Afghanistan, Pakistan, and India in the preparation of curry, to flavour several foods, as preservative, and in perfumery. At therapeutic level, ajwain oil is employed in the treatment of gastrointestinal ailments, lack of appetite and bronchial problems. In the present work, the essential oil of T. ammi growing in Iran was analysed by GC-FID and GC-MS showing thymol (67.4%), p-cymene (17.9%) and γ-terpinene (11.3%) as the major constituents. Afterwards, we investigated the biological effects displayed by ajwain oil, namely the antimicrobial and antioxidant activity, the cytotoxicity on tumour cells, and the induction of lymphocyte proliferation. In addition, the inhibition on nicotinate mononucleotide adenylyltransferase (NadD), which is a promising new target for developing novel antibiotics, was evaluated. The antimicrobial effects of ajwain oil, measured by the agar disc diffusion method, were relevant, with inhibition zones higher than those of reference antibiotics, especially on Staphylococcus aureus and Candida albicans (34.7 and 54.3mm, respectively). This effect was not due to the enzymatic inhibition on NadD. The ajwain oil exhibited a considerable dose-dependent inhibition on the ABTS radical cation, with an IC50 value of 22.4μg/mL. MTT assay revealed that ajwain oil is particularly cytotoxic on colon carcinoma cells, with a IC50 value of 9.6μg/mL. Finally, PBMC proliferation assay revealed some role for the ajwain oil within the network of interactions of the cells of the immune system.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227692 Collegamento a IRIS

2016
Mexican sunflower (Tithonia diversifolia, Asteraceae) volatile oil as a selective inhibitor of Staphylococcus aureus nicotinate mononucleotide adenylyltransferase (NadD)
INDUSTRIAL CROPS AND PRODUCTS
Autore/i: Orsomando, Giuseppe; Agostinelli, Samuele; Bramucci, Massimo; Cappellacci, Loredana; Damiano, Silvia; Lupidi, Giulio; Maggi, Filippo; Ngahang Kamte, Stephane L.; Biapa Nya, Prosper C.; Papa, Fabrizio; Petrelli, Dezemona; Quassinti, Luana; Sorci, Leonardo; Vitali, Luca A.; Petrelli, Riccardo
Classificazione: 1 Contributo su Rivista
Abstract: Tithonia diversifolia, well-known as Mexican sunflower, is an invasive shrub growing in tropical areas of South America, Asia and Africa where it is used as a traditional medicine, ornamental plant and green biomass to improve soil fertility. Given the traditional uses in the treatment of skin infections, we have first analysed the chemical composition and the antimicrobial effects of the essential oil hydrodistilled from inflorescences of T. diversifolia. For the purpose the inhibition zones against a panel of pathogens were measured by the agar diffusion method. In addition, we evaluated the inhibitory effects on several NaMN/NMN adenylyltransferases, which are essential enzymes for NAD biosynthesis in most bacterial pathogens, and also tested the inhibition on the mammalian orthologue enzymes as a promising way to identify novel natural antibiotics. To complete the screening of biological effects, the antioxidant capacity and antiproliferative effects on human tumor cells were evaluated using the DPPH, ABTS, FRAP, and MIT methods. Results showed that T. diversifolia essential oil was mostly active against Staphylococcus aureus with a halo of 14 mm. The essential oil selectively inhibited in vitro the pure NAD biosynthetic enzyme NadD from S. aureus (IC50 of similar to 60 mu g/mL), with basically none or only minor effects on mammalian orthologue enzymes. Finally, the essential oil displayed significant cytotoxic effects on A375, MDA-MB 231, HCT 116 and T98 G tumor cells with IC50 values of 3.02, 3.79, 3.46 and 12.82 mu g/mL, respectively, and noticeable radical scavenging activity on DPPH and ABTS radicals, with IC50 values of 108.8 and 41.7 mu g/mL, respectively.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236815 Collegamento a IRIS

2015
Novel assay identifies Nicotinamide riboside, the form of vitamin B3 that boosts metabolism, as a constituent of milk at levels comparable to Niacin
58th National Meeting of the Italian Society of Biochemistry and Molecular Biology
Autore/i: Ummarino, Simone; Zamporlini, Federica; Ruggieri, Silverio; Mazzola, Francesca; Orsomando, Giuseppe; Amci, Adolfo; Sorci, Leonardo; Raffaelli, Nadia
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/229828 Collegamento a IRIS

2015
Mycobacterial Nicotinate Mononucleotide Adenylyltransferase: STRUCTURE, MECHANISM, AND IMPLICATIONS FOR DRUG DISCOVERY
THE JOURNAL OF BIOLOGICAL CHEMISTRY
Autore/i: Rodionova, Irina A; Zuccola, Harmon J; Sorci, Leonardo; Aleshin, Alexander E; Kazanov, Marat D; Ma, Chen Ting; Sergienko, Eduard; Rubin, Eric J; Locher, Christopher P; Osterman, Andrei L.
Classificazione: 1 Contributo su Rivista
Abstract: Nicotinate mononucleotide adenylyltransferase NadD is an essential enzyme in the biosynthesis of the NAD cofactor, which has been implicated as a target for developing new antimycobacterial therapies. Here we report the crystal structure of Mycobacterium tuberculosis NadD (MtNadD) at a resolution of 2.4 Å. A remarkable new feature of the MtNadD structure, compared with other members of this enzyme family, is a 310 helix that locks the active site in an over-closed conformation. As a result, MtNadD is rendered inactive as it is topologically incompatible with substrate binding and catalysis. Directed mutagenesis was also used to further dissect the structural elements that contribute to the interactions of the two MtNadD substrates, i.e. ATP and nicotinic acid mononucleotide (NaMN). For inhibitory profiling of partially active mutants and wild type MtNadD, we used a small molecule inhibitor of MtNadD with moderate affinity (Ki ∼ 25 μm) and antimycobacterial activity (MIC80) ∼ 40-80 μm). This analysis revealed interferences with some of the residues in the NaMN binding subsite consistent with the competitive inhibition observed for the NaMN substrate (but not ATP). A detailed steady-state kinetic analysis of MtNadD suggests that ATP must first bind to allow efficient NaMN binding and catalysis. This sequential mechanism is consistent with the requirement of transition to catalytically competent (open) conformation hypothesized from structural modeling. A possible physiological significance of this mechanism is to enable the down-regulation of NAD synthesis under ATP-limiting dormancy conditions. These findings point to a possible new strategy for designing inhibitors that lock the enzyme in the inactive over-closed conformation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/225306 Collegamento a IRIS

2015
Regulation of NAD biosynthetic enzymes modulates NAD-sensing processes to shape mammalian cell physiology under varying biological cues
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS
Autore/i: Ruggieri, Silverio; Orsomando, Giuseppe; Sorci, Leonardo; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Abstract: In addition to its role as a redox coenzyme, NAD is a substrate of various enzymes that split the molecule to either catalyze covalent modifications of target proteins or convert NAD into biologically active metabolites. The coenzyme bioavailability may be significantly affected by these reactions, with ensuing major impact on energy metabolism, cell survival, and aging. Moreover, through the activity of the NAD-dependent deacetylating sirtuins, NAD behaves as a beacon molecule that reports the cell metabolic state, and accordingly modulates transcriptional responses and metabolic adaptations. In this view, NAD biosynthesis emerges as a highly regulated process: it enables cells to preserve NAD homeostasis in response to significant NAD-consuming events and it can be modulated by various stimuli to induce, via NAD level changes, suitable NAD-mediated metabolic responses. Here we review the current knowledge on the regulation of mammalian NAD biosynthesis, with focus on the relevant rate-limiting enzymes. This article is part of a Special Issue entitled: Cofactor-dependent proteins: Evolution, chemical diversity and bio-applications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/224700 Collegamento a IRIS

2014
NAD homeostasis in the bacterial response to DNA/RNA damage.
DNA REPAIR
Autore/i: Sorci, Leonardo; Ruggieri, Silverio; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/197102 Collegamento a IRIS

2014
Characterization of bacterial NMN deamidase as a Ser/Lys hydrolase expands diversity of serine amidohydrolases.
FEBS LETTERS
Autore/i: Sorci, Leonardo; Brunetti, L; Cialabrini, L; Mazzola, Francesca; Kazanov, Md; D'Auria, S; Ruggieri, Silverio; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Abstract: NMN deamidase (PncC) is a bacterial enzyme involved in NAD biosynthesis. We have previously demonstrated that PncC is structurally distinct from other known amidohydrolases. Here, we extended PncC characterization by mutating all potential catalytic residues and assessing their individual roles in catalysis through kinetic analyses. Inspection of these residues’ spatial arrangement in the active site, allowed us to conclude that PncC is a serine-amidohydrolase, employing a Ser/Lys dyad for catalysis. Analysis of the PncC structure in complex with a modeled NMN substrate supported our conclusion, and enabled us to propose the catalytic mechanism
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/149702 Collegamento a IRIS

2014
Metabolic and Bactericidal Effects of Targeted Suppression of NadD and NadE Enzymes in Mycobacteria
MBIO
Autore/i: Rodionova, Ia; Schuster, Bm; Guinn, Km; Sorci, Leonardo; Scott, Da; Li, X; Kheterpal, I; Shoen, C; Cynamon, M; Locher, C; Rubin, Ej; Osterman, A. L.
Classificazione: 1 Contributo su Rivista
Abstract: Mycobacterium tuberculosis remains a major cause of death due to the lack of treatment accessibility, HIV coinfection, and drug resistance. Development of new drugs targeting previously unexplored pathways is essential to shorten treatment time and eliminate persistent M. tuberculosis. A promising biochemical pathway which may be targeted to kill both replicating and nonreplicating M. tuberculosis is the biosynthesis of NAD(H), an essential cofactor in multiple reactions crucial for respiration, redox balance, and biosynthesis of major building blocks. NaMN adenylyltransferase (NadD) and NAD synthetase (NadE), the key enzymes of NAD biosynthesis, were selected as promising candidate drug targets for M. tuberculosis. Here we report for the first time kinetic characterization of the recombinant purified NadD enzyme, setting the stage for its structural analysis and inhibitor development. A protein knockdown approach was applied to validate bothNadD and NadE as target enzymes. Induced degradation of either target enzyme showed a strong bactericidal effect which coincided with anticipated changes in relative levels of NaMN and NaAD intermediates (substrates of NadD and NadE, respectively) and ultimate depletion of the NAD(H) pool. A metabolic catastrophe predicted as a likely result of NAD(H) deprivation of cellular metabolism was confirmed by 13C biosynthetic labeling followed by gas chromatography-mass spectrometry (GC-MS) analysis. A sharp suppression of metabolic flux was observed in multiple NAD(P)(H)-dependent pathways, including synthesis of many amino acids (serine, proline, aromatic amino acids) and fatty acids. Overall, these results provide strong validation of the essential NAD biosynthetic enzymes, NadD and NadE, as antimycobacterial drug targets
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/149704 Collegamento a IRIS

2014
Nicotinate phosphoribosyltransferase: a novel antiinfective target?
THE FASEB JOURNAL
Autore/i: Sorci, Leonardo; Anton, Cheltsov; Massaccesi, Luca; Galeazzi, Roberta
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/194902 Collegamento a IRIS

2013
Quinolinate salvage and insights for targeting NAD biosynthesis in group A Streptococci.
JOURNAL OF BACTERIOLOGY
Autore/i: Sorci, Leonardo; Blaby, Ik; Rodionova, Ia; De Ingeniis, J; Tkachenko, S; de Crécy Lagard, V; Osterman, Al
Classificazione: 1 Contributo su Rivista
Abstract: The essential coenzyme NAD plays important roles in metabolic reactions and cell regulation in all organisms. As such, NAD synthesis has been investigated as a source for novel antibacterial targets. Cross-species genomics-based reconstructions of NAD metabolism in group A streptococci (GAS), combined with focused experimental testing in Streptococcus pyogenes, led to a better understanding of NAD metabolism in the pathogen. The predicted niacin auxotrophy was experimentally verified, as well as the essential role of the nicotinamidase PncA in the utilization of nicotinamide (Nm). PncA is dispensable in the presence of nicotinate (Na), ruling it out as a viable antibacterial target. The function of the “orphan” NadC enzyme, which is uniquely present in all GAS species despite the absence of other genes of NAD de novo synthesis, was elucidated. Indeed, the quinolinate (Qa) phosphoribosyltransferase activity of NadC from S. pyogenes allows the organism to sustain growth when Qa is present as a sole pyridine precursor. Finally, the redundancy of functional upstream salvage pathways in GAS species narrows the choice of potential drug targets to the two indispensable downstream enzymes of NAD synthesis, nicotinate adenylyltransferase (NadD family) and NAD synthetase (NadE family). Biochemical characterization of NadD confirmed its functional role in S. pyogenes, and its potential as an antibacterial target was supported by inhibition studies with previously identified class I inhibitors of the NadD enzyme family. One of these inhibitors efficiently inhibited S. pyogenes NadD (sp.NadD) in vitro (50% inhibitory concentration [IC50], 15 M), exhibiting a noncompetitive mechanism with a Ki of 8 M.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/86398 Collegamento a IRIS

2013
Genomics-Guided Analysis of NAD Recycling Yields Functional Elucidation of COG1058 as a New Family of Pyrophosphatases
PLOS ONE
Autore/i: Cialabrini, L.; Ruggieri, Silverio; Kazanov, M. D.; Sorci, Leonardo; Mazzola, Francesca; Orsomando, Giuseppe; Osterman, A. L.; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Abstract: We have recently identified the enzyme NMN deamidase (PncC), which plays a key role in the regeneration of NAD in bacteria by recycling back to the coenzyme the pyridine by-products of its non redox consumption. In several bacterial species, PncC is fused to a COG1058 domain of unknown function, highly conserved and widely distributed in all living organisms. Here, we demonstrate that the PncC-fused domain is endowed with a novel Co+2- and K+-dependent ADP-ribose pyrophosphatase activity, and discuss the functional connection of such an activity with NAD recycling. An in-depth phylogenetic analysis of the COG1058 domain evidenced that in most bacterial species it is fused to PncC, while in a-and some d-proteobacteria, as well as in archaea and fungi, it occurs as a stand-alone protein. Notably, in mammals and plants it is fused to FAD synthase. We extended the enzymatic characterization to a representative bacterial single-domain protein, which resulted to be a more versatile ADP-ribose pyrophosphatase, active also towards diadenosine 5'-diphosphate and FAD. Multiple sequence alignment analysis, and superposition of the available three-dimensional structure of an archaeal COG1058 member with the structure of the enzyme MoeA of the molybdenum cofactor biosynthesis, allowed identification of residues likely involved in catalysis. Their role has been confirmed by site-directed mutagenesis.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/111666 Collegamento a IRIS

2012
NAD biosynthesis enzymes from the bacterial world as valuable tools for vitamin B3 mononucleotides quantitation in mammals
56th National Meeting of the Italian Society of Biochemistry and Molecular Biology
Autore/i: Carradori, R; Mori, V; Amici, Adolfo; Orsomando, Giuseppe; Sorci, Leonardo; Mazzola, F; Bocci, Paola; Ruggieri, Silverio; Raffaelli, Nadia
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/155311 Collegamento a IRIS

2012
Glutamine versus Ammonia Utilization in the NAD Synthetase Family.
PLOS ONE
Autore/i: De Ingeniis, J; Kazanov, Md; Shatalin, K; Gelfand, Ms; Osterman, Al; Sorci, Leonardo
Classificazione: 1 Contributo su Rivista
Abstract: NAD is a ubiquitous and essential metabolic redox cofactor which also functions as a substrate in certain regulatory pathways. The last step of NAD synthesis is the ATP-dependent amidation of deamido-NAD by NAD synthetase (NADS). Members of the NADS family are present in nearly all species across the three kingdoms of Life. In eukaryotic NADS, the core synthetase domain is fused with a nitrilase-like glutaminase domain supplying ammonia for the reaction. This two-domain NADS arrangement enabling the utilization of glutamine as nitrogen donor is also present in various bacterial lineages. However, many other bacterial members of NADS family do not contain a glutaminase domain, and they can utilize only ammonia (but not glutamine) in vitro. A single-domain NADS is also characteristic for nearly all Archaea, and its dependence on ammonia was demonstrated here for the representative enzyme from Methanocaldococcus jannaschi. However, a question about the actual in vivo nitrogen donor for single-domain members of the NADS family remained open: Is it glutamine hydrolyzed by a committed (but yet unknown) glutaminase subunit, as in most ATP-dependent amidotransferases, or free ammonia as in glutamine synthetase? Here we addressed this dilemma by combining evolutionary analysis of the NADS family with experimental characterization of two representative bacterial systems: a two-subunit NADS from Thermus thermophilus and a single-domain NADS from Salmonella typhimurium providing evidence that ammonia (and not glutamine) is the physiological substrate of a typical single-domain NADS. The latter represents the most likely ancestral form of NADS. The ability to utilize glutamine appears to have evolved via recruitment of a glutaminase subunit followed by domain fusion in an early branch of Bacteria. Further evolution of the NADS family included lineage-specific loss of one of the two alternative forms and horizontal gene transfer events. Lastly, we identified NADS structural elements associated with glutamine-utilizing capabilities.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76750 Collegamento a IRIS

2012
S. pyogenes is reliant on salvage of host pyridine precursors for NAD synthesis: implications for pathogenesis and antibacterial intervention
THE FASEB JOURNAL
Autore/i: Sorci, Leonardo; Blaby, Ik; De Crécy Lagard, V; Osterman, A.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/164734 Collegamento a IRIS

2011
NAD biosynthesis under attack
Autore/i: Sorci, Leonardo; Rodionova, I.; Blaby, I. K.; De Ingeniis, J.; De Crécy Lagard, V.; Osterman, A. L.
Classificazione: 5 Altro
Abstract: FASEB RESEARCH CONFERENCE – NAD METABOLISM AND SIGNALING; Lucca, Italy - Speaker and Poster Presenter
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66208 Collegamento a IRIS

2011
Structural biology of NAD metabolism in bacteria
Autore/i: Huang, N.; Eyobo, Y.; Sorci, Leonardo; Osterman, A. L.; Hong, Z.
Classificazione: 5 Altro
Abstract: FASEB RESEARCH CONFERENCE – NAD METABOLISM AND SIGNALING; Lucca (Italy) - Abstract author
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66209 Collegamento a IRIS

2011
The enzyme NMN deamidase of the bacterial pyridine nucleotide cycle is a novel, broadly conserved amidohydrolase
Autore/i: Raffaelli, Nadia; Bocci, P.; Galeazzi, L.; Amici, Adolfo; Brunetti, L.; Ruggieri, Silverio; Reed, S.; Romine, M.; Osterman, A. L.; Rodionov, D.; Sorci, Leonardo
Classificazione: 5 Altro
Abstract: FASEB RESEARCH CONFERENCE – NAD METABOLISM AND SIGNALING; Lucca (Italy) - Abstract author
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66210 Collegamento a IRIS

2011
Eubacterial pyridine nucleotide cycle: identification and characterization of the 'orphan enzyme' nmn deamidase
Febs Journal
Autore/i: Bocci, P.; Galeazzi, L.; Amici, Adolfo; Brunetti, L.; Sorci, Leonardo; Osterman, A.; Romine, M.; Reed, S.; Raffaelli, Nadia
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62369 Collegamento a IRIS

2011
Identification of Nicotinamide Mononucleotide Deamidase of the Bacterial Pyridine Nucleotide Cycle Reveals a Novel Broadly Conserved Amidohydrolase Family
THE JOURNAL OF BIOLOGICAL CHEMISTRY
Autore/i: Galeazzi, Luca; Bocci, P.; Amici, Adolfo; Brunetti, Lucia; Ruggieri, Silverio; Romine, M.; Reed, S.; Osterman, A. L.; Rodionov, D. A.; Sorci, Leonardo; Raffaelli, Nadia
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63609 Collegamento a IRIS

2010
Characterization of the NAD biosynthesis in Francisella tularensis
110th American Society for Microbiology General Meeting 2010: Abstracts
Autore/i: Zogaj, X.; Sorci, Leonardo; Osterman, A. L.; Klose, K. E.
Editore: Curran Associates, Inc
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: 110th GENERAL MEETING OF THE AMERICAN SOCIETY FOR MICROBIOLOGY (ASM); San Diego, CA (USA) - Poster author
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66215 Collegamento a IRIS

2010
Genomics-driven reconstruction of Acinetobacter NAD metabolism: insights for antibacterial target selection
THE JOURNAL OF BIOLOGICAL CHEMISTRY
Autore/i: Sorci, Leonardo; Blaby, I; DE INGENIIS, Jessica; Gerdes, S; Raffaelli, Nadia; DE CRECY LAGARD, V; Osterman, A.
Classificazione: 1 Contributo su Rivista
Abstract: Enzymes involved in the last steps of NAD biogenesis, nicotinate mononucleotide adenylyltransferase (NadD) and NAD synthetase (NadE), are conserved and essential in most bacterial species and are established targets for antibacterial drug development. Our genomics-based reconstruction of NAD metabolism in the emerging pathogen Acinetobacter baumannii revealed unique features suggesting an alternative targeting strategy. Indeed, genomes of all analyzed Acinetobacter species do not encode NadD, which is functionally replaced by its distant homolog NadM. We combined bioinformatics with genetic and biochemical techniques to elucidate this and other important features of Acinetobacter NAD metabolism using a model (nonpathogenic) strain Acinetobacter baylyi sp. ADP1. Thus, a comparative kinetic characterization of PncA, PncB, and NadV enzymes allowed us to suggest distinct physiological roles for the two alternative, deamidating and nondeamidating, routes of nicotinamide salvage/recycling. The role of the NiaP transporter in both nicotinate and nicotinamide salvage was confirmed. The nondeamidating route was shown to be transcriptionally regulated by an ADP-ribose-responsive repressor NrtR. The NadM enzyme was shown to possess dual substrate specificity toward both nicotinate and nicotinamide mononucleotide substrates, which is consistent with its essential role in all three routes of NAD biogenesis, de novo synthesis as well as the two salvage pathways. The experimentally confirmed unconditional essentiality of nadM provided support for the choice of the respective enzyme as a drug target. In contrast, nadE, encoding a glutamine-dependent NAD synthetase, proved to be dispensable when the nondeamidating salvage pathway functioned as the only route of NAD biogenesis.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/30107 Collegamento a IRIS

2010
Genomics and Enzymology of NAD Biosynthesis
Comprehensive Natural Products II Chemistry and Biology
Autore/i: Sorci, Leonardo; Kurnasov, O.; Rodionov, D. A.; Osterman, A. L.
Editore: Elsevier
Luogo di pubblicazione: Oxford
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62364 Collegamento a IRIS

2010
Complexes of Bacterial Nicotinate Mononucleotide Adenylyltransferase with Inhibitors: Implication for Structure-Based Drug Design and Improvement
JOURNAL OF MEDICINAL CHEMISTRY
Autore/i: Huang, N.; Kolhatkar, R.; Eyobo, Y.; Sorci, Leonardo; Rodionova, I.; Osterman, A. L.; Mackerell, A. D.; Zhang, H.
Classificazione: 1 Contributo su Rivista
Abstract: Bacterial nicotinate mononucleotide adenylyltransferase encoded by the essential gene nadD plays a central role in the synthesis of the redox cofactor NAD(+). The NadD enzyme is conserved in the majority of bacterial species and has been recognized as a novel target for developing new and potentially broad-spectrum antibacterial therapeutics. Here we report the crystal structures of Bacillus anthracis NadD in complex with three NadD inhibitors, including two analogues synthesized in the present study. These structures revealed a common binding site shared by different classes of NadD inhibitors and explored the chemical environment surrounding this site. The structural data obtained here also showed that the subtle changes in ligand structure can lead to significant changes in the binding mode, information that will be useful for future structure-based optimization and design of high affinity inhibitors.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62363 Collegamento a IRIS

2009
Targeting NAD biosynthesis in bacterial pathogens. Structure-Based development of Inhibitors of Nicotinate Mononucleotide Adenylyltransferase NadD
Autore/i: Sorci, Leonardo; Pan, Y.; Eyobo, Y.; Rodionova, I. A.; Huang, N.; Kurnasov, O.; Zhong, S.; Mackerell A. . D., Jr; Zhang, H.; Osterman, A. L.
Classificazione: 5 Altro
Abstract: FASEB RESEARCH CONFERENCE – NAD METABOLISM AND SIGNALING; Carefree, AZ (USA)- Speaker and Poster presenter
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66205 Collegamento a IRIS

2009
Ammonia is the Physiological Substrate of ‘GAT-less’ Prokaryotic NAD Synthetase
Autore/i: De Ingeniis, J.; Sorci, Leonardo; Kazanov, M.; Kustu, S.; Osterman, A. L.
Classificazione: 5 Altro
Abstract: FASEB RESEARCH CONFERENCE – NAD METABOLISM AND SIGNALING; Carefree, AZ (USA) - Author
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66207 Collegamento a IRIS

2009
Targeting NAD biosynthesis in bacterial pathogens: Structure-based development of inhibitors of nicotinate mononucleotide adenylyltransferase NadD
CHEMISTRY & BIOLOGY
Autore/i: Sorci, Leonardo; Pan, Y.; Eyobo, Y.; Rodionova, I.; Huang, N.; Kurnasov, O.; Zhong, S.; Mackerell, A. D.; Zhang, H.; Osterman, A. L.
Classificazione: 1 Contributo su Rivista
Abstract: The emergence of multidrug-resistant pathogens necessitates the search for new antibiotics acting on previously unexplored targets. Nicotinate mononucleotide adenylyltransferase of the NadD family, an essential enzyme of NAD biosynthesis in most bacteria, was selected as a target for structure-based inhibitor development. Using iterative in silico and in vitro screens, we identified small molecule compounds that efficiently inhibited target enzymes from Escherichia coli (ecNadD) and Bacillus anthracis (baNadD) but had no effect on functionally equivalent human enzymes. On-target antibacterial activity was demonstrated for some of the selected inhibitors. A 3D structure of baNadD was solved in complex with one of these inhibitors (3_02), providing mechanistic insights and guidelines for further improvement. Most importantly, the results of this study help validate NadD as a target for the development of antibacterial agents with potential broad-spectrum activity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62365 Collegamento a IRIS

2009
Nicotinamide mononucleotide synthetase is the key enzyme for an alternative route of NAD biosynthesis in Francisella tularensis.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Autore/i: Sorci, Leonardo; Martynowski, D; Rodionov, Da; Eyobo, Y; Zogaj, X; Klose, Ke; Nikolaev, Ev; Magni, Giulio; Zhang, H; Osterman, Al
Classificazione: 1 Contributo su Rivista
Abstract: Enzymes involved in the last 2 steps of nicotinamide adenine dinucleotide (NAD) cofactor biosynthesis, which catalyze the adenylylation of the nicotinic acid mononucleotide (NaMN) precursor to nicotinic acid dinucleotide (NaAD) followed by its amidation to NAD, constitute promising drug targets for the development of new antibiotics. These enzymes, NaMN adenylyltransferase (gene nadD) and NAD synthetase (gene nadE), respectively, are indispensable and conserved in nearly all bacterial pathogens. However, a comparative genome analysis of Francisella tularensis allowed us to predict the existence of an alternative route of NAD synthesis in this category A priority pathogen, the causative agent of tularaemia. In this route, the amidation of NaMN to nicotinamide mononucleotide (NMN) occurs before the adenylylation reaction, which converts this alternative intermediate to the NAD cofactor. The first step is catalyzed by NMN synthetase, which was identified and characterized in this study. A crystal structure of this enzyme, a divergent member of the NadE family, was solved at 1.9-A resolution in complex with reaction products, providing a rationale for its unusual substrate preference for NaMN over NaAD. The second step is performed by NMN adenylyltransferase of the NadM family. Here, we report validation of the predicted route (NaMN --> NMN --> NAD) in F. tularensis including mathematical modeling, in vitro reconstitution, and in vivo metabolite analysis in comparison with a canonical route (NaMN --> NaAD --> NAD) of NAD biosynthesis as represented by another deadly bacterial pathogen, Bacillus anthracis.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76763 Collegamento a IRIS

2008
A novel route of NAD synthesis is uncovered in Francisella tularensis
Autore/i: Sorci, Leonardo; Martynowski, D.; Rodionov, D. A.; Eyobo, Y.; Zogaj, X.; Klose, K. E.; Nikolaev, E. V.; Magni, G.; Zhang, H.; Osterman, A. L.
Classificazione: 5 Altro
Abstract: GORDON RESEARCH CONFERENCE – ENZYMES, COENZYMES AND METABOLIC PATHWAYS, Biddeford, ME (USA) - Poster presenter
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66203 Collegamento a IRIS

2008
Glutamate exposure of cortical neurons evokes initial oxidation of NADPH in mitochondria followed by a delayed oxidation of NADH: Delayed redox and calcium deregulation
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
Autore/i: Gerencser, A. A.; Doczi, J.; Sorci, Leonardo; Nicholls, D. G.; Adam Vizi, V.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62368 Collegamento a IRIS

2008
Transcriptional regulation of NAD metabolism in bacteria: genomic reconstruction of NiaR (YrxA) regulon
NUCLEIC ACIDS RESEARCH
Autore/i: Rodionov, D. A.; Li, X.; Rodionova, I.; Yang, C.; Sorci, Leonardo; Dervyn, E.; Martynowski, D.; Zhang, H.; Gelfand, M. S.; Osterman, A. L.
Classificazione: 1 Contributo su Rivista
Abstract: A comparative genomic approach was used to reconstruct transcriptional regulation of NAD biosynthesis in bacteria containing orthologs of Bacillus subtilis gene yrxA, a previously identified niacin-responsive repressor of NAD de novo synthesis. Members of YrxA family (re-named here NiaR) are broadly conserved in the Bacillus/Clostridium group and in the deeply branching Fusobacteria and Thermotogales lineages. We analyzed upstream regions of genes associated with NAD biosynthesis to identify candidate NiaR-binding DNA motifs and assess the NiaR regulon content in these species. Representatives of the two distinct types of candidate NiaR-binding sites, characteristic of the Firmicutes and Thermotogales, were verified by an electrophoretic mobility shift assay. In addition to transcriptional control of the nadABC genes, the NiaR regulon in some species extends to niacin salvage (the pncAB genes) and includes uncharacterized membrane proteins possibly involved in niacin transport. The involvement in niacin uptake proposed for one of these proteins (re-named NiaP), encoded by the B. subtilis gene yceI, was experimentally verified. In addition to bacteria, members of the NiaP family are conserved in multicellular eukaryotes, including human, pointing to possible NaiP involvement in niacin utilization in these organisms. Overall, the analysis of the NiaR and NrtR regulons (described in the accompanying paper) revealed mechanisms of transcriptional regulation of NAD metabolism in nearly a hundred diverse bacteria.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62371 Collegamento a IRIS

2008
Bifunctional NMN adenylyltransferase/ADP-ribose pyrophosphatase: structure and function in bacterial NAD metabolism.
STRUCTURE
Autore/i: Huang, N; Sorci, Leonardo; Zhang, X; Brautigam, Ca; Li, X; Raffaelli, Nadia; Magni, Giulio; Grishin, Nv; Osterman, Al; Zhang, H.
Classificazione: 1 Contributo su Rivista
Abstract: Bacterial NadM-Nudix is a bifunctional enzyme containing a nicotinamide mononucleotide (NMN) adenylyltransferase and an ADP-ribose (ADPR) pyrophosphatase domain. While most members of this enzyme family, such as that from a model cyanobacterium Synechocystis sp., are involved primarily in nicotinamide adenine dinucleotide (NAD) salvage/recycling pathways, its close homolog in a category-A biodefense pathogen, Francisella tularensis, likely plays a central role in a recently discovered novel pathway of NAD de novo synthesis. The crystal structures of NadM-Nudix from both species, including their complexes with various ligands and catalytic metal ions, revealed detailed configurations of the substrate binding and catalytic sites in both domains. The structure of the N-terminal NadM domain may be exploited for designing new antitularemia therapeutics. The ADPR binding site in the C-terminal Nudix domain is substantially different from that of Escherichia coli ADPR pyrophosphatase, and is more similar to human NUDT9. The latter observation provided new insights into the ligand binding mode of ADPR-gated Ca2+ channel TRPM2.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76768 Collegamento a IRIS

2007
THE DIFFERENTIAL BIOCHEMICAL PROPERTIES OF NICOTINAMIDE MONONUCLEOTIDE ADENYLYLTRANSFERASE ISOZYMES ENABLE TO DETERMINE THEIR RELATIVE EXPRESSION LEVELS
ITALIAN JOURNAL OF BIOCHEMISTRY
Autore/i: Scotti, S.; Di Stefano, M.; Cimadamore, F.; Sorci, Leonardo; Mazzola, F.; Magni, G.
Editore: Biomedia
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62367 Collegamento a IRIS

2007
NAD(+) and axon degeneration revisited: Nmnat1 cannot substitute for Wld(S) to delay Wallerian degeneration.
CELL DEATH AND DIFFERENTIATION
Autore/i: Conforti, L; Fang, G; Beirowski, B; Wang, Ms; Sorci, Leonardo; Asress, S; Adalbert, R; Silva, A; Bridge, K; Huang, Xp; Magni, Giulio; Glass, Jd; Coleman, Mp
Classificazione: 1 Contributo su Rivista
Abstract: The slow Wallerian degeneration protein (Wld(S)), a fusion protein incorporating full-length nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1), delays axon degeneration caused by injury, toxins and genetic mutation. Nmnat1 overexpression is reported to protect axons in vitro, but its effect in vivo and its potency remain unclear. We generated Nmnat1-overexpressing transgenic mice whose Nmnat activities closely match that of Wld(S) mice. Nmnat1 overexpression in five lines of transgenic mice failed to delay Wallerian degeneration in transected sciatic nerves in contrast to Wld(S) mice where nearly all axons were protected. Transected neurites in Nmnat1 transgenic dorsal root ganglion explant cultures also degenerated rapidly. The delay in vincristine-induced neurite degeneration following lentiviral overexpression of Nmnat1 was significantly less potent than for Wld(S), and lentiviral overexpressed enzyme-dead Wld(S) still displayed residual neurite protection. Thus, Nmnat1 is significantly weaker than Wld(S) at protecting axons against traumatic or toxic injury in vitro, and has no detectable effect in vivo. The full protective effect of Wld(S) requires more N-terminal sequences of the protein.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76775 Collegamento a IRIS

2007
Initial-rate kinetics of human NMN-adenylyltransferases: substrate and metal ion specificity, inhibition by products and multisubstrate analogues, and isozyme contributions to NAD+ biosynthesis.
BIOCHEMISTRY
Autore/i: Sorci, Leonardo; Cimadamore, F; Scotti, S; Petrelli, R; Cappellacci, L; Franchetti, P; Orsomando, Giuseppe; Magni, Giulio
Classificazione: 1 Contributo su Rivista
Abstract: Initial-rate and product inhibition studies revealed distinctive ordered ternary complex kinetic mechanisms, substrate specificities, and metal ion preferences for the three isozymes of human nicotinamide mononucleotide adenylyl-transferase (NMNAT, EC 2.7.7.1). ATP binds before NMN with nuclear isozyme NMNAT1 and Golgi apparatus NMNAT2, but the opposite order is observed with the mitochondrial isozyme NMNAT3. Only the latter utilizes ITP efficiently in place of ATP, and while NMNH conversion to NADH by NMNAT1 and NMNAT3 occurs at similar rates, conversion by NMNAT2 is much slower. These isozymes can also be discriminated by their action on tiazofurin monophosphate (TrMP), a metabolite of the antineoplastic prodrug tiazofurin. Our finding that TrMP is only a substrate with NMNAT1 and NMNAT3 reveals for the first time an organelle selectivity in the metabolism of this important drug. In search of additional ways to discriminate these isozymes, we synthesized and tested the P1-(nicotinamide/nicotinate-riboside-5')-Pn-(adenosine-5') dinucleotides Np3AD, Np4AD, and Nap4AD. In addition to being highly effective inhibitors, these multisubstrate geometric inhibitors gave inhibition patterns that are consistent with the aforementioned isozyme differences in substrate binding order. Distinctive differences in their substrate specificity and metal ion selectivity also permitted us to quantify individual isozyme contributions to NAD+ formation in human cell extracts.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76779 Collegamento a IRIS

2006
Functions of the shared N-terminus of slow wallerian degeneration (WldS) and Ube4b proteins: a sequence required for axon protection and ubiquitination
Autore/i: Conforti, L.; Laser, H.; Beirowski, B.; Morreale, G.; Adalbert, R.; Sorci, Leonardo; Bridge, K.; Mack, T.; Heyer, M.; Wishart, T. M.; Haley, J. E.; Ribchester, R. R.; Plomann, M.; Coleman, M. P.
Classificazione: 5 Altro
Abstract: 5th FORUM OF EUROPEAN NEUROSCIENCE; Vienna (Austria) - abstract author
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/66255 Collegamento a IRIS

2005
Synthesis and biological evaluation of NAD analogs as human pyridine nucleotide adenylyltransferase inhibitors.
NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS
Autore/i: Franchetti, P; Petrelli, R; Cappellacci, L; Pasqualini, M; Vita, P; Sorci, Leonardo; Mazzola, F; Raffaelli, Nadia; Magni, Giulio
Classificazione: 1 Contributo su Rivista
Abstract: NAD analogs modified at the ribose adenylyl moiety, named N-2'-MeAD and Na-2'-MeAD, were synthesized as ligands of pyridine nucleotide (NMN/NaMN) adenylyltransferase (NMNAT). Both dinucleotides resulted selective inhibitors against human NMNAT-3 isoenzyme
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76773 Collegamento a IRIS

2004
Characterization of Mycobacterium tuberculosis NAD kinase: functional analysis of the full-length enzyme by site-directed mutagenesis.
BIOCHEMISTRY
Autore/i: Raffaelli, Nadia; Finaurini, L; Mazzola, F; Pucci, L; Sorci, Leonardo; Amici, Adolfo; Magni, Giulio
Classificazione: 1 Contributo su Rivista
Abstract: NAD kinase is the only known enzyme catalyzing the formation of NADP, a coenzyme implicated in most reductive biosynthetic reactions and in many antioxidant defense systems. Despite its importance, nothing is known regarding its structure or mechanism of catalysis. Mycobacterium tuberculosis NAD kinase has been overexpressed in Escherichia coli and purified to homogeneity. The molecular and kinetic properties of the enzyme resulted in significant differences from those reported by others on a proteolytically degraded form of the protein. Indeed the full-length enzyme displays an allosteric behavior and shows a strict preference for inorganic polyphosphate as the phosphate donor. It is inhibited by the reaction product NADP and by both NADH and NADPH. The mycobacterial enzyme shares with all other known NAD kinases a highly conserved region (spanning residues 189-210), particularly rich in glycines, which differs from the primary sequences of all previously identified nucleotide-binding sites. Alanine-scanning mutagenesis performed on 11 conserved residues within this domain revealed its importance in catalysis. A total of 6 of 11 mutated proteins completely lost the enzymatic activity while retaining the same oligomeric state of the wild-type protein, as demonstrated by gel-filtration analysis. Substitutions of S199 and G208 with alanine rendered enzyme versions with reduced activity. Their kinetic characterization, performed on purified proteins, revealed kinetic parameters toward ATP and polyphosphate similar to those of the wild-type enzyme. On the contrary, when the kinetic analysis was performed by using NAD as the variable substrate, significant differences were observed with respect to both the allosteric behavior and the catalytic efficiency, suggesting that the mutated region is likely involved in NAD binding.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/76777 Collegamento a IRIS

2003
Mycobacterium tuberculosis NAD (P) BIOSYNTHETIC ENZYMES AS NOVEL ANTIMICROBIAL DRUG TARGETS
ITALIAN JOURNAL OF BIOCHEMISTRY
Autore/i: Raffaelli, Nadia; Sorci, Leonardo; Mazzola, Francesca; Amici, Adolfo; Emanuelli, Monica; Magni, Giulio
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/62366 Collegamento a IRIS

2002
Cloning and characterization of a new human NMN adenylyltransferase.
Atti XV Convegno Nazionale “I Processi di ADP-ribosilazione”.
Autore/i: Sorci, Leonardo; Raffaelli, Nadia; Mazzola, F.; Amici, Adolfo; Emanuelli, Monica; Magni, Giulio
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80562 Collegamento a IRIS

2002
Identification of a novel human nicotinamide mononucleotide adenylyltransferase
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Autore/i: Raffaelli, Nadia; Sorci, Leonardo; Amici, Adolfo; Emanuelli, Monica; Mazzola, F; Magni, Giulio
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/50996 Collegamento a IRIS

2001
Clonaggio ed espressione di geni da Mycobacterium tuberculosis coinvolti nella sintesi del NAD.
Atti Workshop dell’Istituto Nazionale Biostrutture e Biosistemi su “Biotecnologie”.
Autore/i: Mazzola, F.; Raffaelli, Nadia; Sorci, Leonardo; Amici, Adolfo; Emanuelli, Monica; Magni, Giulio
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80556 Collegamento a IRIS

2001
Biosintesi del NAD in Mycobacterium tubercolosis: clonaggio ed espressione dei geni nadD e nadR.
Atti Riunione annuale Gruppo Nucleotidi e Acidi Nucleici della Società Italiana di Biochimica.
Autore/i: Mazzola, F.; Raffaelli, Nadia; Sorci, Leonardo; Amici, Adolfo; Emanuelli, Monica; Magni, Giulio
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80559 Collegamento a IRIS

2001
Una nuova NMN adeniltrasferasi umana: clonaggio, espressione eterologa e caratterizzazione della proteina KIAA0479.
Atti Workshop dell’Istituto Nazionale Biostrutture e Biosistemi su “Biotecnologie”.
Autore/i: Sorci, Leonardo; Raffaelli, Nadia; Mazzola, F.; Amici, Adolfo; Emanuelli, Monica; Magni, Giulio
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/80555 Collegamento a IRIS




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