title: New substrates for beta-lactam-recognizing enzymes: aryl malonamates.
abstract: Aryl malonamates are demonstrated to be novel substrates of a broad range of beta-lactam-recognizing enzymes. These compounds are isomers of the aryl phenaceturates, which are well-known substrates of these enzymes, but the new compounds contain a retro-amide side chain. Several lines of evidence, including comparisons of steady-state kinetic parameters between enzymes and a detailed investigation of the methanolysis kinetics, solvent deuterium isotope effects, and pH-rate profile for turnover of a retro substrate by the Enterobacter cloacae P99 beta-lactamase, suggested that the new substrates are likely to be hydrolyzed by the same chemical mechanisms as "normal" substrates. Molecular modeling indicated that the retro-amide group fits snugly into the active site of the P99 beta-lactamase by hydrogen bonding to the conserved lysine-67 residue. The retro-amide side chain may represent a lead to novel mechanism-based and transition state analogue inhibitors.
authors.affiliation: SIRCOB, UMR CNRS 8086, Université de Versailles, Saint Quentin-en-Yvelines, Bâtiment Lavoisier, 45 Avenue des Etats Unis, F-7800, Versailles, France.
authors.forename: D
authors.initials: D
authors.lastname: Cabaret
authors.forename: S A
authors.initials: SA
authors.lastname: Adediran
authors.forename: R F
authors.initials: RF
authors.lastname: Pratt
authors.forename: M
authors.initials: M
authors.lastname: Wakselman
mesh_terms: D000215:Acylation; D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D002384:Catalysis; D003903:Deuterium / Q000737:chemistry; D016972:Enterobacter cloacae / Q000201:enzymology; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008239:Lysine / Q000737:chemistry / Q000378:metabolism; D008314:Malonates / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D013379:Substrate Specificity; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D000577:Amides; D008314:Malonates; D003903:Deuterium; D001618:beta-Lactamases; D008239:Lysine