Inactivation of yeast pyruvate decarboxylase in the presence of substrate and quinone electron acceptors
Vovk, A.I.; Parkhomenko, I.M.; Murav'eva, I.V.; Protasova, Z.S.
Ukrainskii Biokhimicheskii Zhurnal 68(2): 105-109
1996
ISSN/ISBN: 0201-8470 PMID: 9005652 Document Number: 466278
The rate constants of paracatalytic inactivation of pyruvate decarboxylase in the presence of 1,4-naphthoquinones and 1,4-benzoquinones are determined by redox potentials of the oxidant. The logarithm of k2 depends hyperbolically on the redox potential of quinone E0(Q/Q-.) with the coefficient of proportionality which approximates 8.4, The absence of considerable deviations in this correlation for the oxidants of different structures with closed values Eo(Q/Q-.) indicates that the enzyme produces no additional steric barrier.