title: Purification and biochemical properties of beta-lactamase produced by Proteus rettgeri.
abstract: beta-Lactamase produced by Proteus rettgeri was found to be a typical cephalosporin beta-lactamase on the basis of its substrate hydrolysis profile. The enzyme activity was enhanced by prior treatment with an inducer.  The enzyme was purified 166-fold by carboxymethyl-Sephadex column chromatography which indicated that its molecular weight was 42,000 +/- 2,000 and its isoelectric point was 8.7. Cefoperazone, cefoxitin, cefusulodin, cefmetazole, cefotaxime, 6059-S, FK749, YM-09330, carbenicillin, and cloxacillin were stable to this enzyme and possessed the function of competitive inhibition, as shown by their affinity for the beta-lactamase. The enzyme activity was inhibited by iodine, p-chloromerburibenzoate, and HG2+ ion. Clavulanic acid and CP-45899 displayed poor inhibitory activity toward this enzyme. The optimal pH was 8.0, and the optimal temperature was 50 degrees C.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism; D004352:Drug Resistance, Microbial; D008970:Molecular Weight; D011511:Proteus / Q000201:enzymology*; D001618:beta-Lactamases / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases