Gosset Beta-lactamase enzyme Overview
Beta-lactamase enzyme is a bacterial enzyme that catalyzes hydrolysis of the β-lactam ring present in β-lactam antibiotics, which include penicillins, cephalosporins, monobactams, and carbapenems, thereby inactivating their antibacterial activity. This enzymatic mechanism is a primary mode of antibiotic resistance in many clinically important Gram-negative and some Gram-positive bacteria. Beta-lactamases are classified into four molecular classes (A, B, C, D) based on sequence homology: classes A, C, and D use an active site serine, while class B enzymes are metallo-β-lactamases requiring zinc ions[2][5][1]. These enzymes are a major therapeutic target both for antibiotic development (new β-lactams less susceptible to hydrolysis) and for β-lactamase inhibitors (to protect antibiotics from degradation)[3][5][7]. The expanding diversity of β-lactamases and their mobile genetic elements have contributed significantly to the crisis of multidrug-resistant bacterial infections worldwide.
Mechanism of Action
Hydrolysis of the β-lactam ring of antibiotics, rendering them inactive[3][5]; For serine β-lactamases (classes A, C, D): formation of an acyl-enzyme intermediate via a serine residue; For metallo-β-lactamases (class B): hydrolysis mediated via one or two active site zinc ions without acylation[1][2][5]
Biological Functions
Disease Associations
Safety Considerations
- Rapid dissemination and diversification of β-lactamase enzymes among pathogenic bacteria
- Resistance to broad classes of antibiotics, severely limiting therapeutic options[3][5]
- Therapeutic failure in infections caused by β-lactamase-producing bacteria
Interacting Drugs
Associated Biomarkers
| Biomarker |
|---|
| β-lactamase gene detection (e.g., blaTEM, blaSHV, blaCTX-M, blaNDM, blaKPC, blaIMP, blaVIM) |
| Phenotypic tests for β-lactamase activity in clinical isolates |