The Role of Active Site Flexible Loops in Catalysis and of Zinc in Conformational Stability of Bacillus cereus 569/H/9 β-Lactamase.

ABSTRACT: Metallo-β-lactamases catalyze the hydrolysis of most β-lactam antibiotics and hence represent a major clinical concern. The development of inhibitors for these enzymes is complicated by the diversity and flexibility of their substrate-binding sites, motivating research into their structure and function. In this study, we examined the conformational properties of the Bacillus cereus β-lactamase II in the presence of chemical denaturants using a variety of biochemical and biophysical techniques. The apoenzyme was found to unfold cooperatively, with a Gibbs free energy of stabilization (ΔG(0)) of 32 ± 2 kJ·mol(-1) For holoBcII, a first non-cooperative transition leads to multiple interconverting native-like states, in which both zinc atoms remain bound in an apparently unaltered active site,

SUBMITTER: Montagner C 

PROVIDER: S-EPMC4965562 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature