Korean Journal of Microbiology (미생물학회지)
- Volume 29 Issue 4
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- Pages.230-237
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- 1991
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- 0440-2413(pISSN)
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- 2383-9902(eISSN)
Purification and Characterization of Nonmitochondrial Citrate Synthase from Saccharomyces cerevisiae
Saccharomyces cerevisiae의 Nonmitochondrial Citrate synthase 분리 및 특성
Abstract
Citrate synthase 1 (mitochondrial) and citrate synthase 2 (nonmitochondrial) were purified from Saccharomyces cerevisiae. The physical and enzymatic characteristics of citrate synthase 2 were ananlyzed in comparison with citrate synthase 1. Both isoenzymes were shown to be dimeric proteins of identical subunits, and the molecular weights of the subunits were estimated to be 48.3kDa for citrate synthase 1 and 47.0kDa for citrate synthase 2, respectively. The optimal pH value for enzyme activity was pH 7.5 for both isoenzymes. However, the optimal temperature for the activity was strikingly different; while the activity of citrate synthase 1 reached its peak at 65.deg.C, that of citrate synthase 2 was maximal at 40.deg.C. Citrate synthase 2 showed much lower thermal and pH stability than citrate synthase 1. In addition, citrate synthase 2 was affected much more by the metal ions such as