title: [Inhibition of pyruvate kinase of bovine adrenal cortex by ATP: the role of magnesium].
abstract: The effect of ATP on bovine adrenal cortex pyruvate kinase has been studied. ATP is a competitive inhibitor of the enzyme, the Ki being 3.2 mM. Based on the efficiency of tryptophan fluorescence quenching, it was concluded that the magnesium complex of ATP is a true enzyme inhibitor. The role of Mg2+ in the inhibition process consists in the formation of a bridge between the enzyme and ATP. The ATP-dependent mechanism of pyruvate kinase inhibition is a potential physiological regulator of the enzyme determining the lower threshold of its sensitivity in vivo.
authors.forename: V V
authors.initials: VV
authors.lastname: Vinogradov
authors.forename: Iu V
authors.initials: IuV
authors.lastname: Iarotskiĭ
authors.forename: I B
authors.initials: IB
authors.lastname: Zavodnik
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000302:Adrenal Cortex / Q000201:enzymology*; D000818:Animals; D002413:Cations, Divalent; D002417:Cattle; D007700:Kinetics; D008274:Magnesium / Q000502:physiology*; D011770:Pyruvate Kinase / Q000037:antagonists & inhibitors*
chemical_list: D002413:Cations, Divalent; D000255:Adenosine Triphosphate; D011770:Pyruvate Kinase; D008274:Magnesium