Beta-lactamase

Function

Beta-lactamase (Blac) are enzymes which make bacteria resistant to β-lactam antibiotics by breaking their β-lactam ring. Blac are classified according to their resistance targets.

• Class A are broad-spectrum
  
• Class B are metalloenzymes
  
• Class C are cephalosporinases
  
• Class D are cloxacilanases
  
• Carbapenemase (Car) are Blac with wide hydrolytic capacities. Car can hydrolyze penicillins, cephalosporins, monobactams and carbapenems.
  
• Extended-spectrum Blac class A (ESBL) hydrolyze penicillins but not cephalosporins.

Relevance

Blac makes some bacteria resistant to antibiotics like penicillin, cephamycin and carbapenems.

Structural highlights

The active site of class B Blac contains 2 Zn+2 ions.