bacteria contain several isofunctional , beta-lactam sensitive membrane enzymes engaged in the synthesis of cell wall peptidoglycan ( peptidoglycan-dd-carboxypeptidases , -transpeptidases , -endopeptidases ) as members of sets of even more numerous membrane proteins with specific , high binding-affinity for beta-lactam antibiotics ( penicillin-binding proteins , pbps ) .
C0014442
enzymes
C0030946
endopeptidases