[Effect of thiamine phosphates on the activity of regulatory enzymes of the pyruvate dehydrogenase complex].
The effect of thiamine triphosphate (ThTP) and thiamine diphosphate (ThDP) on the activity of rat liver pyruvate dehydrogenase complex regulatory enzymes (kinase and phosphatase) was studied in experiments with isolated enzyme preparations. It is shown that ThDP caused a pronounced activation of pyruvate dehydrogenase phosphatase (Ka is equal to 65.0 nM). ThTP inhibits phosphatase competitively against the substrate--the phosphorylated pyruvate dehydrogenase complex. The both thiamine phosphates inhibit the pyruvate dehydrogenase kinase activity almost similarly in concentrations exceeding 10 microM. The physiological significance of the antagonistic action of ThDP and ThTP on the pyruvate dehydrogenase phosphatase activity is discussed.
Parkhomenko
Iu M
IuM
Chernysh
I Iu
IIu
Churilova
T Ia
TIa
Khalmuradov
A G
AG
D000818:Animals; D004789:Enzyme Activation; D066298:In Vitro Techniques; D007700:Kinetics; D008930:Mitochondria, Liver / Q000201:enzymology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D011769:Pyruvate Dehydrogenase (Lipoamide)-Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011768:Pyruvate Dehydrogenase Complex / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity; D013831:Thiamine / Q000031:analogs & derivatives*; D013835:Thiamine Pyrophosphate / Q000494:pharmacology*; D013838:Thiamine Triphosphate / Q000494:pharmacology*
D047428:Protein Kinase Inhibitors; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D011768:Pyruvate Dehydrogenase Complex; D013838:Thiamine Triphosphate; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases; D011769:Pyruvate Dehydrogenase (Lipoamide)-Phosphatase; D013835:Thiamine Pyrophosphate; D013831:Thiamine
Vliianie tiaminfosfatov na aktivnost' reguliatornykh fermentov piruvatdegidrogenaznogo kompleksa.