title: Synthesis and characterisation of a ligand that forms a stable tetrahedral intermediate in the active site of the Aureobacterium species (-) gamma-lactamase.
abstract: The crystal structure of a (-) gamma-lactamase from an Aureobacterium species showed a molecule bound covalently to the active site serine residue. This enzyme complex represented the first structure of a stably bound tetrahedral intermediate for an alpha/beta hydrolase fold enzyme. The structural elucidation of tetrahedral intermediates is important for the understanding of enzymatic mechanism, substrate recognition and enzyme inhibition. In this paper, we report the synthesis and subsequent characterisation of (3aR,7aS)-3a,4,7,7a-tetrahydrobenzo-[1,3]-dioxol-2-one (BD1), the molecule modelled into the Aureobacterium (-) gamma-lactamase active site. This molecule has been confirmed to be an inhibitor and to be displaced from the enzyme by the racemic gamma-lactam substrate.
authors.affiliation: Henry Wellcome Building for Biocatalysis, University of Exeter, Exeter, UKEX4 4QD.
authors.forename: Stephen
authors.initials: S
authors.lastname: Connelly
authors.forename: Kirsty
authors.initials: K
authors.lastname: Line
authors.forename: Michail N
authors.initials: MN
authors.lastname: Isupov
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Littlechild
mesh_terms: D039903:Actinobacteria / Q000201:enzymology*; D000581:Amidohydrolases / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D001665:Binding Sites; D005021:Ethylamines / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008956:Models, Chemical; D011487:Protein Conformation; D011759:Pyrrolidines / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005021:Ethylamines; D008024:Ligands; D011759:Pyrrolidines; C085527:BD 1008; D000581:Amidohydrolases; C401943:gamma-lactamase