Serine-type beta-lactamase enzyme (None)

Serine-type beta-lactamases are bacterial enzymes that confer resistance to beta-lactam antibiotics (such as penicillins and cephalosporins) by hydrolyzing the characteristic beta-lactam ring of these drugs, rendering them inactive. These enzymes utilize a serine residue in their active site as a nucleophile for catalysis, distinguishing them from metallo-beta-lactamases, which require metal ions. They are classified into Ambler classes A, C, and D based on sequence similarity and structural features. By breaking down β-lactams before they can inhibit cell wall synthesis enzymes (PBPs), these enzymes provide bacteria with robust resistance against many frontline antibiotics. Inhibition strategies focus on molecules that covalently modify key active-site residues or target structurally conserved regions.

Acylation–deacylation using nucleophilic active-site serine