Beta-Lactamase Ambler Class A (Class A Beta-Lactamase)

Beta-Lactamase Ambler Class A Overview

Beta-lactamase enzymes are bacterial enzymes that hydrolyze and inactivate beta-lactam antibiotics, leading to antibiotic resistance. The Ambler classification system divides beta-lactamases into four classes (A–D) based on amino acid sequence homology. Ambler class A beta-lactamases are serine-based enzymes that use a conserved serine residue (Ser70) as a nucleophile to attack the carbonyl carbon of the amide bond in the β-lactam ring of antibiotics. This reaction results in cleavage of the β-lactam ring, rendering the antibiotic ineffective. Class A enzymes can hydrolyze penicillins, most cephalosporins, monobactams, and some carbapenems. Common pathogens producing class A beta-lactamases include *Klebsiella pneumoniae*, *Escherichia coli*, and *Pseudomonas aeruginosa*. Many class A beta-lactamases are inhibited by classical inhibitors such as clavulanic acid or tazobactam.

Mechanism of Action

Hydrolyzes β-lactam ring of antibiotics, rendering them ineffective against penicillin-binding proteins (PBPs).

Biological Functions

Safety Considerations

Interacting Drugs