Upon preincubation with halogenated isoxazolyl-penicillins, the activity of Bacillus cereus beta-lactamase is decreased by a factor proportional to the inhibitor concentration. This inactivation, which concerns essentially the catalytic rate constant of the enzyme, occurs only at or above 37 degrees C with cloxacillin and dicloxacillin, and even at 25 degrees C with flucloxacillin. The dependence of the inactivation rate upon inhibitor concentration is consistent, in the former case, with the occurrence of a bimolecular reaction, and in the latter case, with a bimolecular process followed by a monomolecular step.
Inactivation of Bacillus cereus beta-lactamase by halogenated isoxazolylpenicillins / Strom, Roberto; Giampiero, Ravagnan; Vincenzo, Salfi. - In: EUROPEAN JOURNAL OF BIOCHEMISTRY. - ISSN 0014-2956. - STAMPA. - 62:1(1976), pp. 95-101. [10.1111/j.1432-1033.1976.tb10101.x]
Inactivation of Bacillus cereus beta-lactamase by halogenated isoxazolylpenicillins.
STROM, Roberto;
1976
Abstract
Upon preincubation with halogenated isoxazolyl-penicillins, the activity of Bacillus cereus beta-lactamase is decreased by a factor proportional to the inhibitor concentration. This inactivation, which concerns essentially the catalytic rate constant of the enzyme, occurs only at or above 37 degrees C with cloxacillin and dicloxacillin, and even at 25 degrees C with flucloxacillin. The dependence of the inactivation rate upon inhibitor concentration is consistent, in the former case, with the occurrence of a bimolecular reaction, and in the latter case, with a bimolecular process followed by a monomolecular step.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
