Unexpected influence of ionic strength on branched-pathway interactions between beta-lactamases and beta-halogenopenicillanates.
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.
De Meester
F
F
Laboratoires de Microbiologie et d'Enzymologie, Université de Liège, Belgium.
Matagne
A
A
Dive
G
G
Frère
J M
JM
D007700:Kinetics; D009994:Osmolar Concentration; D010397:Penicillanic Acid / Q000378:metabolism* / Q000031:analogs & derivatives; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism
D065093:beta-Lactamase Inhibitors; C018008:brobactam; D010397:Penicillanic Acid; C031528:6-iodopenicillanic acid; D001618:beta-Lactamases