L6170

β-Lactamase

recombinant, expressed in E. coli

• Synonym(s): Carbapenemase, Cephalosprinase
• CAS Number: 9073-60-3
• Enzyme Commission number: 3.5.2.6 (BRENDA, IUBMB)
• EC Number: 232-970-8
• UNSPSC Code: 12352204
• NACRES: NA.54

Properties

• recombinant: expressed in E. coli
• Quality Level: 200
• form: powder
• specific activity: ≥20 U/mg (with cephalosporin C); ≥400 U/mg (with benzylpenicilin)
• storage temp.: 2-8°C

Description

General description

β-Lactamase produced by bacteria is closely related to the penicillin binding proteins. β-Lactamase hydrolyzes β-lactum antibiotics and is the prime cause of resistance development by bacteria. There are four subclasses of β-Lactamases. Classes A, C and D form an acyl-enzyme via active site serine residue. Class B β-lactamases are metalloenzymes with zinc ion at their active site for β-lactam hydrolysis. Mutations in the β-lactamases has resulted in the generation of extended-spectrum β-lactamases (ESBLs). As close to 900 types of β-Lactamases are produced by microbes.

Application

β--lactamase is used to inactivate β-lactam antibiotics by breaking open the β-lactam ring. β--lactamase is used to study antibiotic resistance and resistance suppression. Product L6170 is recombinantly produced based on the sequence of the enzyme from Pseudomonas aeruginosa, and is expressed in E. coli.

β-Lactamase has been used in coumarin-cephalosporin-fluorescein-acetoxymethyl (CCF4)- β-Lactamase assay in dendritic cells and in the hydrolysis of meropenem (H-Mer) to generate 18O-labeled H-Mer.

Biochem/physiol Actions

β--lactamase inactivates β-lactam antibiotics by breaking open the β-lactam ring. Typical analysis for other substrates: ceftriaxon 2-4 un/mg; cefazolin 2-4 un/mg; ceftazidime 1.5-3 un/mg; cefoxitin 0.35-0.7 un/mg; cefepime 1.2-2.4 un/mg; cefuroxime 1.5-3 un/mg; cefotaxime 1-2 un/mg, oxacillin 4-8 un/mg; imipenem 1.2-2.4 un/mg; and meropenem 3-6 un/mg

Typical analysis for other substrates: ceftriaxon 2-4 un/mg; cefazolin 2-4 un/mg; ceftazidime 1.5-3 un/mg; cefoxitin 0.35-0.7 un/mg; cefepime 1.2-2.4 un/mg; cefuroxime 1.5-3 un/mg; cefotaxime 1-2 un/mg, oxacillin 4-8 un/mg; imipenem 1.2-2.4 un/mg; and meropenem 3-6 un/mg

Unit Definition

One unit will hydrolyze 1.0 μmole substrate per min (βI: benzylpenicillin; βII: cephalosporin C) in 50 mM phosphate buffer, pH 7.0 containing 10 μM zinc chloride at 25 ºC.

Physical form

Lyophilized powder containing sodium chloride and potassium phosphate.

Safety Information

• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable