Energization of mitochondrial inner membranes caused by L-malate.
It was found that 0.06 mug antimycin A/mg mitochondrial protein, an amount sufficient to inhibit electron transfer between cytochromes b and c1 completely, fully reversed the oxidation of cytochrome a caused by L-malate in anaerobic mitochondria. The effect of L-malate on cytochrome a was insensitive to oligomycin, but all the uncouplers and detergents tested reversed the oxidation of cytochrome a caused by L-malate in anaerobic mitochondria. It was also found that addition of L-malate to anaerobic mitochondria, like addition of ATP, decreased the fluorescence of 1-anilinonaphthalene-8-sulphonate, and that subsequent addition of uncouplers reversed this effect. The effect of L-malate on the fluorescence of the dye was insensitive to oligomycin. The present findings suggest that addition of L-malate may cause energization of the mitochondrial inner membranes and that the oxidation of cytochrome a caused by L-malate in anaerobic mitochondria may result from an L-malate-induced, energy-linked reversal of electron transfer in site II.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000693:Anaerobiosis; D000817:Anilino Naphthalenesulfonates / Q000378:metabolism; D000818:Animals; D000968:Antimycin A / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D003580:Cytochromes / Q000378:metabolism; D008293:Malates / Q000494:pharmacology*; D008566:Membranes / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D009840:Oligomycins / Q000494:pharmacology; D010086:Oxidative Phosphorylation Coupling Factors / Q000494:pharmacology; D010101:Oxygen Consumption; D051381:Rats
D000817:Anilino Naphthalenesulfonates; D003580:Cytochromes; D008293:Malates; D009840:Oligomycins; D010086:Oxidative Phosphorylation Coupling Factors; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000968:Antimycin A; D000255:Adenosine Triphosphate