title: A catalytic mechanism for cysteine N-terminal nucleophile hydrolases, as revealed by free energy simulations.
abstract: The N-terminal nucleophile (Ntn) hydrolases are a superfamily of enzymes specialized in the hydrolytic cleavage of amide bonds. Even though several members of this family are emerging as innovative drug targets for cancer, inflammation, and pain, the processes through which they catalyze amide hydrolysis remains poorly understood. In particular, the catalytic reactions of cysteine Ntn-hydrolases have never been investigated from a mechanistic point of view. In the present study, we used free energy simulations in the quantum mechanics/molecular mechanics framework to determine the reaction mechanism of amide hydrolysis catalyzed by the prototypical cysteine Ntn-hydrolase, conjugated bile acid hydrolase (CBAH). The computational analyses, which were confirmed in water and using different CBAH mutants, revealed the existence of a chair-like transition state, which might be one of the specific features of the catalytic cycle of Ntn-hydrolases. Our results offer new insights on Ntn-mediated hydrolysis and suggest possible strategies for the creation of therapeutically useful inhibitors.
authors.affiliation: Pharmaceutical Department, University of Parma, Parma, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Lodola
authors.forename: Davide
authors.initials: D
authors.lastname: Branduardi
authors.forename: Marco
authors.initials: M
authors.lastname: De Vivo
authors.forename: Luigi
authors.initials: L
authors.lastname: Capoferri
authors.forename: Marco
authors.initials: M
authors.lastname: Mor
authors.forename: Daniele
authors.initials: D
authors.lastname: Piomelli
authors.forename: Andrea
authors.initials: A
authors.lastname: Cavalli
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D019295:Computational Biology / Q000379:methods; D056004:Molecular Dynamics Simulation; D009154:Mutation; D017433:Protein Structure, Secondary
chemical_list: D000581:Amidohydrolases; C438834:N-terminal nucleophile hydrolase