Bacterial penicillin-binding protein (transpeptidase) (None)

Bacterial penicillin-binding proteins (PBPs), specifically those with transpeptidase activity, are a family of membrane-associated enzymes essential for the biosynthesis of peptidoglycan, the main structural component of bacterial cell walls. They catalyze transglycosylation (polymerization of glycan strands) and transpeptidation (cross-linking peptide side chains) reactions. PBPs are the targets of β-lactam antibiotics, which inhibit their enzymatic function, disrupting cell wall synthesis and leading to bacterial lysis. Most bacteria possess multiple PBP isoforms, which can complicate the development of highly selective inhibitors.

Other names

PBPTranspeptidase

β-Lactam antibiotics bind to PBPs' active sites, forming stable acyl-enzyme complexes that irreversibly inhibit enzyme activity by covalently modifying key serine residues. This blocks cross-linking reactions required for proper cell wall assembly leading to bacterial lysis due to osmotic instability.