Like other beta-lactam antibiotics,<unk>  acts by inhibiting the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of gram-positive bacteria. It does this by binding to and competitively inhibiting the transpeptidase enzyme (also known as penicillin-binding proteins (PBPs)). These PBPs crosslink glycopeptides (D-alanyl-alanine), forming the peptidoglycan cell wall.<unk>  and other β-lactam antibiotics are structural analogs of D-alanyl-alanine, and the transpeptidase enzymes that bind to them are sometimes called penicillin-binding proteins (PBPs).<unk>  is actually a penicillinase-resistant B-lactam antibiotic. Penicillinase is a bacterial enzyme produced by bacteria resistant to other B-lactam antibiotics which hydrolyses the antibiotic, rendering it nonfunctional.<unk>  is not bound and hydrolysed by penicillinase, meaning it can kill the bacteria, even if this enzyme is present.
Methicillin
Ampicillin
Tetracycline
Erythromycin
Natamycin
Piperacillin
Carbenicillin
Cethromycin