title: Overexpression, purification, and characterization of human and bovine mitochondrial ATPase inhibitors: comparison of the properties of mammalian and yeast ATPase inhibitors.
abstract: Mitochondrial ATP synthase (F1F0-ATPase) is regulated by an intrinsic ATPase inhibitor protein. In this study, we overexpressed and purified human and bovine ATPase inhibitors and their properties were compared with those of a yeast inhibitor. The human and bovine inhibitors inhibited bovine ATPase in a similar way. The yeast inhibitor also inhibited bovine F1F0-ATPase, although the activity was about three times lower than the mammalian inhibitors. All three inhibitors inhibited yeast F1F0-ATPase in a similar way. The activities of all inhibitors decreased at higher pH, but the magnitude of the decrease was different for each combination of inhibitor and ATPase. The results obtained in this study show that the inhibitory mechanism of the inhibitors was basically shared in yeast and mammals, but that mammalian inhibitors require unique residues, which are lacking in the yeast inhibitor, for their maximum inhibitory activity. Common inhibitory sites of mammalian and yeast inhibitors are suggested.
authors.affiliation: Department of Food and Nutrition, Faculty of Human Life Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan. ichikawa@life.osaka-cu.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Ichikawa
authors.forename: Chikae
authors.initials: C
authors.lastname: Ogura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D025261:Mitochondrial Proton-Translocating ATPases / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000235:genetics; D011506:Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D000097795:ATPase Inhibitory Protein
chemical_list: D004791:Enzyme Inhibitors; D025261:Mitochondrial Proton-Translocating ATPases; D011506:Proteins; D000097795:ATPase Inhibitory Protein; C474451:F1F0-ATP synthase