In vitro biosynthesis of bacterial peptidoglycan using D-Cys-containing precursors: fluorescent detection of transglycosylation and transpeptidation

摘要

Peptidoglycan precursors containing D-Cys at position 4 were polymerised to form a synthetic peptidoglycan layer, which could be fluorescently labelled, providing a new method to monitor peptidoglycan transglycosylation and transpeptidation.rnThe final steps of bacterial peptidoglycan biosynthesis, occurring on the exterior of the cytoplasmic membrane, are important targets for antibacterial chemotherapy. Transglycosylation of lipid intermediate II to form immature peptidoglycan is catalysed by the glycosyltransferase domain of class A penicillin binding proteins (PBPs), and is inhibited by moenomycin and vancomycin. Transpeptidation to form mature peptidoglycan is catalysed by the transpeptidase domains of class A and class B PBPs, and is the target for the β-lactam family of antibiotics.