Essential arginines in mercuric reductase isolated from Yersinia enterocolitica 138A14. |
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| Authors: | M Blaghen M S el Kebbaj D J Vidon D Tritsch |
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| Institution: | Laboratoire de Biochimie, Faculté des Sciences I Université Hassan II, Casablanca, Morocco. |
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| Abstract: | The mercuric reductase from Yersinia enterocolitica 138A14 was inactivated by the arginine modifying reagents 2,3-butanedione and phenylglyoxal. The inactivation by 2,3-butanedione exhibited second order kinetics with rate constant of 32 min-1 M-1. In the case of phenylglyoxal, biphasic kinetics were observed. The oxidized coenzyme (NADP+) prevented inactivation of the enzyme by the alpha-dicarbonyl reagents, whereas the reduced coenzyme (NADPH) enhanced the inactivation rate. The loss of enzyme activity was related to the incorporation of 2-14C] phenylglyoxal; when two arginines per subunit were modified the enzyme was completely inactivated. |
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