Is there a plasma membrane-located anion-sensitive ATPase? IV. Distribution of the enzyme in rat pancreas.
The intracellular localization of anion-sensitive Mg2+-ATPase in rat pancreas was studied by differential centrifugation, density gradient centrifugation and by the use of inhibitors of mitochondrial Mg2+-ATPase. The anion-sensitive MG2+-ATPase appears to be localized almost exclusively in a mitochondrial (15 min, 15 000 times g) fraction which shows two peaks after density gradient centrifugation. Both peaks coincide with the highest levels of cytochrome c oxidase activity, but not with alkaline phosphatase, (Na+ plus K+)-ATPase and leucine aminopeptidase activities or RNA. They appear to be equal sensitive to inhibition by oligomycin, aurovertin D and the rat liver mitochondrial inhibitor protein, at least when 1 mM EDTA is present in the isolation media. We conclude that no significant plasma membrane-located anion-sensitive Mg2+-ATPase activity is present in rat pancreas.
D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology*; D002712:Chlorides / Q000494:pharmacology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology; D009840:Oligomycins / Q000494:pharmacology; D010179:Pancreas / Q000201:enzymology*; D051381:Rats
D001639:Bicarbonates; D002712:Chlorides; D009840:Oligomycins; D000251:Adenosine Triphosphatases; D008274:Magnesium