title: Partial purification and characterization of succinyl-CoA synthetase from Saccharomyces cerevisiae.
abstract: Succinyl-CoA synthetase from Saccharomyces cerevisiae was partially purified (20-fold) with a yield of 44%. The Michaelis-Menten constants were determined: Km (succinate) = 17 mM; Km (ATP) = 0.13 mM; Km (CoA) = 0.03 mM. The succinyl-CoA synthetase has a molecular weight of about 80000 dalton (as determined by polyacrylamide gradient gel electrophoresis). The pH optimum is at 6.0. During fermentation the activity of succinyl-CoA synthetase is lower than in aerobically grown yeast cells. The presence of succinyl-CoA synthetase in fermenting yeasts may be regarded as an indication for the oxidative formation of succinate. In fermenting yeast cells succinyl-CoA synthetase is repressed by glucose if ammonium sulphate serves as nitrogen source. This catabolite repression is not observed with disaccharides or when amino acids are used as nitrogen source.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000693:Anaerobiosis; D003066:Coenzyme A Ligases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013389:Succinate-CoA Ligases / Q000302:isolation & purification / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid; D013696:Temperature
chemical_list: D013386:Succinates; D000255:Adenosine Triphosphate; D019802:Succinic Acid; D003066:Coenzyme A Ligases; D013389:Succinate-CoA Ligases