title: An acyl-thioesterase from yeast mitochondria.
abstract: A previously unstudied acyl-coenzyme A thioesterase activity has been demonstrated in submitochondrial particles from Saccharomyces cerevisiae. The preferred substrate for the enzyme activity is oleoyl-coenzyme A. Tests with inhibitors of the thioesterase showed that, in addition to common thiol inhibitors, the oxidative phosphorylation inhibitors oligomycin and venturicidin also blocked thioesterase activity. Purification of the enzyme catalyzing this activity revealed that thioesterase copurified with mitochondrial ATPase. When thioesterase was isolated from oxidative phosphorylation mutants selected for resistance to these two inhibitors, thioesterase activity was also resistant. The results suggest that thioester hydrolysis may be catalyzed by components associated with the isolated ATPase complex. Further attempts to link this activity to in vivo function of ATPase were not successful.
mesh_terms: D005033:Ethylmaleimide / Q000494:pharmacology; D007700:Kinetics; D008627:Mercuric Chloride; D008628:Mercury / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology*; D009840:Oligomycins / Q000494:pharmacology; D010170:Palmitoyl-CoA Hydrolase; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013379:Substrate Specificity; D013816:Thermodynamics; D013869:Thiolester Hydrolases; D014698:Venturicidins / Q000494:pharmacology
chemical_list: D009840:Oligomycins; D014698:Venturicidins; D008627:Mercuric Chloride; D013869:Thiolester Hydrolases; D010170:Palmitoyl-CoA Hydrolase; D008628:Mercury; D005033:Ethylmaleimide