Features of thiamine diphosphate-dependent enzyme inhibition by oxodihydrothiochrome and its phosphorylated derivatives
Zimatkina, T.I.; Chernikevich, I.P.; Zabrodskaia, S.V.; Kuznetsova, A.S.; Oparin, D.A.; Stepuro, I.I.; Ostrovskiĭ, I.M.
Ukrainskii Biokhimicheskii Zhurnal 63(2): 59-65
1991
ISSN/ISBN: 0201-8470 PMID: 1882465 Document Number: 379386
Anticoenzyme action of new derivatives of thiamine: oxodihydrothiochrome and its mono- and diphosphoric esters has been studied in the experiments on mice. It is shown that the given compounds exert an inhibiting action on transketolase and pyruvate dehydrogenase and do not change activity of 2-oxoglutarate dehydrogenase in the animal organism. Antivitamin effect of the studied inhibitors is observed with the lower doses and in the earlier terms as compared with the other known inhibitors of thiamine-diphosphate-dependent enzymes. The preparations inhibit activity of the yeast pyruvate-decarboxylase by the mixed (with respect to thiamine-diphosphate) type (Ki for oxodihydrothiochrome and its mono- and diphosphoric esters: 2.3 x 10(-3), 7.2 x 10(-4), 5.6 x 10(-5) M, respectively). Possible mechanisms of the action of the mentioned compounds as thiamine antimetabolites are discussed.