[Reactivation of the partially phosphorylated pyruvate dehydrogenase complex from bovine adrenal glands].
The partially phosphorylated pyruvate dehydrogenase complex from adrenal glands is reactivated in the presence of Mg2+ (or Mn2+) and Ca2+. During selective chelation of Ca2+ with EGTA the reactivation rate is sharply decelerated. However, in the absence of Mg2+ or Mn2+ Ca2+ do not virtually induce reactivation of the pyruvate dehydrogenase complex. The apparent Km' value for Mg2+ is the same in the media with and without Ca2+ and is equal to 1.2 mM. The Km' value for Mn2+ is 0.35 mM. The optimal concentration of Ca2+ is 0.5 mM. The highest reactivation rate is observed in the presence of Mn2+ and Ca2+. The inhibition of the time-dependent reactivation of the pyruvate dehydrogenase complex by phosphate and fluoride ions provides evidence for the process being accomplished by the complex-bound regulatory enzyme, phosphatase.
D000311:Adrenal Glands / Q000201:enzymology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D004789:Enzyme Activation; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D010766:Phosphorylation; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*
D011768:Pyruvate Dehydrogenase Complex; D008345:Manganese; D008274:Magnesium; D002118:Calcium
Izuchenie reaktivatsii chastichno fosforilirovannogo piruvatdegidrogenaznogo kompleksa iz nadpochechnykh zhelez byka.