Regulation of ATP hydrolysis in liver mitochondria from ground squirrel

• Published in: FEBS letters Vol. 266; no. 1; pp. 83 - 86
• Main Authors: Bronnikov, G.E., Vinogradova, S.O., Chernyak, B.V.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 18.06.1990
• Subjects: Adenosine Triphosphatases - metabolism; Adenosine Triphosphate - metabolism; Animals; ATP; ATPase inhibitor protein; Calcium - metabolism; Calcium ion; CCCP, carbonyl cyanide m-chlorophenylhydrazone; Copper - pharmacology; Ground squirrel; H super(+)-transporting ATPase; Hibernation; Hydrogen-Ion Concentration; liver; Liver mitochondria; Mitochondria, Liver - metabolism; Sciuridae - metabolism; TTFB, 4,5,6,7-tetrachloro-2-trifluoromethyl benzimidazole; Uncoupling; Uncoupling Agents - pharmacology; Zinc - pharmacology; Uncoupling; CCCP, carbonyl cyanide m-chlorophenylhydrazone; Calcium ion; Hibernation; ATPase inhibitor protein; TTFB, 4,5,6,7-tetrachloro-2-trifluoromethyl benzimidazole; Liver mitochondria; Ground squirrel
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(90)81512-M

The uncoupler-induced inactivation of H +-ATPase in liver mitochondria from ground squirrel has been studied. The dependence of this process on Δ \ ̄ gmH +, pH and ATP indicates that it is caused by the protein inhibitor. This conclusion is also supported by the protective effect of Zn 2+ and Cu 2+. The inactivation can be induced by Ca 2+ at low concentrations in the presence of phosphate. It is shown that the protein inhibitor inactivates ATPase almost completely under optimal conditions while its effect in mice or rat liver mitochondria does not exceed 30%. The potential efficiency of the inhibitor's action does not depend on either the season or the state of animals (hibernating or active). At the same time, the sensitivity of this system to Ca 2+ is significantly lower in active (summer) animals.