The pH-dependence of class B and class C β-lactamases
- 1 July 1983
- journal article
- research article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 213 (1), 61-66
- https://doi.org/10.1042/bj2130061
Abstract
The classification by structure allots .beta.-lactamases to (at present) 3 classes, A, B and C. The pH-dependence of the kinetic parameters for class B and class C was determined. They differ from each other and from class A .beta.-lactamases. The class B enzyme was .beta.-lactamase II from Bacillus cereus 569/H/9. The plots of kcat against pH for the hydrolysis of benzylpenicillin by Zn(II)-requiring .beta.-lactamase II and Co(II)-requiring .beta.-lactamase II were not symmetrical, but those of kcat/Km were. A similar feature was observed for the hydrolysis of benzylpenicillin and cephalosporin C by a class C .beta.-lactamase from Pseudomonas aeruginosa. The results were interpreted by a scheme in which 2 ionic forms of an intermediate can give a product, but do so at differing rates.This publication has 28 references indexed in Scilit:
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