title: Activation of a complex of ATPase with the natural protein inhibitor in submitochondrial particles.
abstract: Almost all ATPase molecules in submitochondrial particles, isolated from beef heart mitochondria in the presence of MgATP, are in an active complex with the natural protein inhibitor (IF1). In de-energized particles at high ionic strength a slow and irreversible ATPase activation is found to occur due to a dissociation of the enzyme-inhibitor complex. The pH-dependence of this process points out that deprotonation of IF1 molecule is an essential step in the dissociation of the complex. Zn2+ sharply accelerates ATPase activation, probably via binding with the deprotonated form of IF1. ATPase activation is completely prevented by MgATP, indicating the formation of a transient enzyme-inhibitor complex retaining ATPase activity.
authors: A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, USSR.
authors: Khodjaev EYu
authors: F B
authors: FB
authors: Komarnitsky
authors: G
authors: G
authors: Capozza
authors: V F
authors: VF
authors: Dukhovich
authors: B V
authors: BV
authors: Chernyak
authors: S
authors: S
authors: Papa
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D004789:Enzyme Activation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D008929:Mitochondria, Heart / Q000201:enzymology; D009947:Organotin Compounds / Q000494:pharmacology; D009994:Osmolar Concentration; D011506:Proteins / Q000378:metabolism*; D013367:Submitochondrial Particles / Q000201:enzymology; D013431:Sulfates / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology; D000097795:ATPase Inhibitory Protein
chemical_list: D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate; D002118:Calcium; D008274:Magnesium; D009947:Organotin Compounds; D011506:Proteins; D013431:Sulfates; D015032:Zinc; D000097795:ATPase Inhibitory Protein; C031512:potassium sulfate; C030665:triphenyltin