title: Unexpected influence of ionic strength on branched-pathway interactions between beta-lactamases and beta-halogenopenicillanates.
abstract: Ionic strength strongly influenced the turnover/inactivation ratio in the interaction between beta-halogenopenicillanates and some class A beta-lactamases. This suggested the stabilization of a highly charged intermediate by solvation. Those data could be interpreted on the basis of a reaction pathway where an episulphonium ion was transiently formed. The various mechanisms proposed for explaining the formation of the dihydrothiazine chromophore are discussed.
authors.affiliation: Laboratoires de Microbiologie et d'Enzymologie, Université de Liège, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: De Meester
authors.forename: A
authors.initials: A
authors.lastname: Matagne
authors.forename: G
authors.initials: G
authors.lastname: Dive
authors.forename: J M
authors.initials: JM
authors.lastname: Frère
mesh_terms: D007700:Kinetics; D009994:Osmolar Concentration; D010397:Penicillanic Acid / Q000378:metabolism* / Q000031:analogs & derivatives; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D065093:beta-Lactamase Inhibitors; C018008:brobactam; D010397:Penicillanic Acid; C031528:6-iodopenicillanic acid; D001618:beta-Lactamases