β-Lactamase, Bacillus cereus 569/H9

β-Lactamase produced by bacteria shares sequence homology to penicillin-binding proteins. This enzyme is found in Gram-negative bacteria. β-Lactamases have four molecular classes, named A, B, C, and D. A, C, and D form an acyl-enzyme via active site serine residue. Class B β-lactamases are metalloenzymes, which have a zinc ion at their active site for β-lactam hydrolysis.

β-Lactamase hydrolyzes β-lactum antibiotics and is the chief cause of resistance to β-lactam antibiotics development by bacteria. Mutations in the β-lactamases are associated with extended-spectrum β-lactamases (ESBLs).

Following reconstitution, store in the refrigerator (4°C). Stock solutions are stable for up to 1 month at 4°C.

One unit is defined as the amount of enzyme that will hydrolyze 1.0 µmol benzyl penicillin and 1.0 µmol of cephalosporin C, respectively, per min at 25°C.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

Toxicity: Harmful (C)