Serine β-Lactamase

Serine β-lactamases are a family of bacterial enzymes that hydrolyze β-lactam antibiotics, conferring resistance. They are classified into classes A, C, and D, and utilize a serine residue in their active site for catalysis. The mechanism involves acylation and deacylation steps, leading to antibiotic inactivation. Inhibition strategies involve drugs like clavulanic acid, tazobactam, and avibactam, which form acyl-enzyme complexes or inhibit the enzyme through other mechanisms. They are a major contributor to antibiotic resistance.

Other names

PenicillinaseCephalosporinaseOxacillinaseSBL

Acylation–deacylation using nucleophilic attack by active-site serine. The nucleophilic serine is activated by a general base and attacks the carbonyl carbon, generating an acylenzyme intermediate.