The affinity of impienem (N-formimidoylthienamycin) for the penicillin-binding proteins of Staphylococcus aureus. Binding and release.

Abstract

Penicillin-binding proteins 1, 2 and 3 in S. aureus possess common properties. All have very strong affinities for benzylpenicillin and imipenem (N-formimidoylthienamycin) and all have an activity which releases bound imipenem, but not bound benzylpenicillin. Lower MW penicillin-binding protein 4, which has a rather weak affinity for benzylpenicillin and also weak penicillinase activity showed an extraordinarily high affinity for imipenem, but no antibiotic-releasing activity.