title: Physical and enzymatic properties of nucleotide-depleted beef heart mitochondrial adenosine triphosphatase.
abstract: Tightly bound adenine nucleotides are removed from multiple binding sites on beef heart mitochondrial ATPase (F1) by chromatography on columns of Sephadex equilibrated with 50% glycerol. Release of nucleotides from the enzyme is associated with large decreases in sedimentation velocity (from 11.9 S to 8.4 S) which may be observed in concentrated solutions of polyols. Polyol-induced conformational changes are reversed when the enzyme is returned to dilute buffers. The nucleotide-depleted enzyme restores oxidative phosphorylation in F1-deficient submitochondrial particles. Reconstitution of nucleotide-depleted F1 with the ATP analog (adenylyl-imidodiphosphate (AMP-PNP), almost 5 moles of AMP-PNP per mole of enzyme, results in preparations with substantially inhibited ATPase activity which nevertheless restores oxidative phosphorylation and the 32Pi-ATP exchange reaction in F1-deficient submitochondrial particles. Incubation of the analog-labeled enzyme with ATP and Mg++ results in partial displacement of the analog and a time-dependent recovery of ATPase activity.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000032:analysis / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000266:Adenylyl Imidodiphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D008931:Mitochondria, Muscle / Q000201:enzymology*; D009206:Myocardium / Q000201:enzymology*; D010085:Oxidative Phosphorylation; D011487:Protein Conformation / Q000187:drug effects; D013395:Sucrose / Q000494:pharmacology
chemical_list: D000227:Adenine Nucleotides; D000266:Adenylyl Imidodiphosphate; D013395:Sucrose; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases