Effects of some alcohols on the conformation of mitochondrial H+-ATPase complex and F1-ATPase from pig heart.
The conformations of the H+-ATPase complex and F1-ATPase in low concentrations of methanol, ethanol, n-propanol, iso-propanol and t-butanol were studied by circular dichroism. For F1-ATPase, all but methanol first increased and then decreased the circular dichroism magnitude of helical bands as the alcohol concentration was increased. With ethanol, n-propanol, iso-propanol and t-butanol, the alpha-helix content reached a maximum at about 5% alcohol and began to decrease at 10%. The content of beta-sheet showed the opposite effect, reaching a minimum at 5% and increasing slightly at higher concentrations. None of the alcohols studied had a significant effect on the conformation of the H+-ATPase complex. This difference implies that the alcohols had a greater effect on free F1-ATPase than on the membrane-bound F1-ATPase. The hydrophobic protein F0 and the membrane lipids in the H+-ATPase complex may stabilize and protect F1 from the effects of the alcohols.
D000433:1-Propanol / Q000494:pharmacology; D000438:Alcohols / Q000494:pharmacology*; D000818:Animals; D000440:Butanols / Q000494:pharmacology; D002942:Circular Dichroism; D000431:Ethanol / Q000494:pharmacology; D000432:Methanol / Q000494:pharmacology; D008929:Mitochondria, Heart / Q000201:enzymology*; D011487:Protein Conformation / Q000187:drug effects; D006180:Proton-Translocating ATPases; D013552:Swine; D020002:tert-Butyl Alcohol
D000438:Alcohols; D000440:Butanols; D000431:Ethanol; D000433:1-Propanol; D006180:Proton-Translocating ATPases; D020002:tert-Butyl Alcohol; D000432:Methanol