Investigation of the interactions between beta-lactams and a metallo-beta-lactamase from bacillus cereus using a monoclonal antibody

A monoclonal antibody recognizing the active site of a beta-lactamase from Bacillus cereus was identified and characterized. The binding of the monoclonal antibody to the active site was quantitatively inhibited by a broad spectrum of beta-lactam antibiotics. The levels of inhibition were found to be associated with particular structural features of the antibiotics and their ability to form stable enzyme/substrate complexes. A novel, broad specificity assay for beta-lactams was developed based on the inhibition of antibody binding of all the beta-lactams studied. The assay is applicable to detection of beta-lactams at or close to the MRL level and would be complementary to existing receptor-based assays. The approach described is relevant to the study of kinetic aspects of beta-lactamases and could prove a useful tool in future drug development.