title: Penicillanic acid sulfone: nature of irreversible inactivation of RTEM beta-lactamase from Escherichia coli.
abstract: When penicillanic acid sulfone in large molar excess is incubated with the RTEM beta-lactamase, the enzyme becomes inactivated irreversibly. From studies of the consequential spectroscopic changes, from the use of specifically tritiated penicillanic acid sulfone, and from comparison by isoelectric focusing of the enzyme after inactivation by the sulfone and by clavulanic acid, the inactivated enzyme appears to be cross-linked by a beta-aminoacrylate fragment deriving from C-5, C-6, and C-7 of the original beta-lactam. Model studies on the behavior of alcoholic solutions of penicillanic acid sulfone in the presence of amines are entirely consistent with this interpretation.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D004355:Drug Stability; D004926:Escherichia coli / Q000201:enzymology*; D007525:Isoelectric Focusing; D010397:Penicillanic Acid / Q000494:pharmacology*; D013053:Spectrophotometry; D013407:Sulbactam; D014316:Tritium; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases
chemical_list: D002969:Clavulanic Acids; D065093:beta-Lactamase Inhibitors; D014316:Tritium; D019818:Clavulanic Acid; D010397:Penicillanic Acid; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1; D013407:Sulbactam