Inactivation of beta-lactamase from Shigella flexneri UCSF-129 by 6-beta-iodopenicillanic acid: classification of the enzyme.
The beta-lactamase from Shigella flexneri UCSF-129 was irreversible inactivated by 6-beta-iodopenicillanic acid. Only one serine residue was modified, according to the spectra change and the amino acid analyses. A pH variation of 0.3 units was found when the chemically modified enzyme was submitted to isoelectric focusing. The inactivation constant of the fast time course reaction was 0.1 seg-1. Protection of 96% was obtained, using cephradine 2,830 times more concentrated than 6-beta-iodopenicillanic acid. It is suggested that this enzyme belongs to class A, according to Ambler (1980).
Campos
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Department of Chemistry, Faculty of Sciences, University of Concepción, Casilla, Chile.
Alarcón
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M
González
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H
D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D010397:Penicillanic Acid / Q000737:chemistry / Q000494:pharmacology* / Q000031:analogs & derivatives; D012763:Shigella flexneri / Q000201:enzymology*; D065093:beta-Lactamase Inhibitors
D065093:beta-Lactamase Inhibitors; D010397:Penicillanic Acid; C031528:6-iodopenicillanic acid