Investigation of the interactions between β-lactams and a metallo-β-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. (C) 2001 Academic Press.