Studies on acetyl-coenzyme A synthetase of yeast: inhibition by long-chain acyl-coenzyme A esters.
Long-chain acyl-coenzyme A (CoA) compounds (palmityl, stearyl, and oleyl) were found to be potent inhibitors of acetyl-CoA synthetase (ACS) of Saccharomyces cerevisiae strain LK2G12 from aerobic, but not from nonaerobic, cells. The effectiveness of the inhibitors of the aerobic enzyme was in the following order: palmityl-CoA < stearyl-CoA < oleyl-CoA. Short-chain acyl-CoA compounds (propionyl, butyryl, and valeryl) and long-chain fatty acids had no effect on ACS from either source. The inhibition by oleyl-CoA was found to be dependent on enzyme concentration, whereas the inhibition by palmityl- and stearyl-CoA was independent of ACS concentration. Inhibition by palmityl-CoA was noncompetitive with respect to both acetate and CoA, and with increasing concentration of inhibitor the pattern was sigmoidal, with a Hill value of 3.24. At maximally inhibitory concentrations of palmityl-CoA, a small amount of enzyme activity remained. This noninhibitable enzyme in aerobic cells was shown not to be of nonaerobic origin.
D000085:Acetates / Q000494:pharmacology; D000215:Acylation; D000332:Aerobiosis; D000693:Anaerobiosis; D002458:Cell Fractionation; D003065:Coenzyme A / Q000494:pharmacology*; D003066:Coenzyme A Ligases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004952:Esters / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology; D006898:Hydroxylamines / Q000494:pharmacology; D008861:Microsomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D009829:Oleic Acids; D010169:Palmitic Acids; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development; D013229:Stearic Acids
D000085:Acetates; D004952:Esters; D005230:Fatty Acids, Nonesterified; D006898:Hydroxylamines; D009829:Oleic Acids; D010169:Palmitic Acids; D013229:Stearic Acids; D003066:Coenzyme A Ligases; D003065:Coenzyme A