Partial purification and characterization of succinyl-CoA synthetase fromSaccharomyces cerevisiae

✍ Scribed by H. Schwartz; H. -O. Steitz; F. Radler

• Publisher: Springer Netherlands
• Year: 1983
• Tongue: English
• Weight: 511 KB
• Volume: 49
• Category: Article
• ISSN: 0003-6072
• DOI: 10.1007/bf00457881

✦ Synopsis

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.