排硫硫杆菌的磷酸烯醇丙酮酸羧化酶。I. 一般特性。

Phosphoenolpyruvate carboxylase of Thiobacillus thioparus. I. General properties.

作者信息

Hoban D J, Lyric R M

出版信息

Can J Biochem. 1975 Aug;53(8):875-80. doi: 10.1139/o75-119.

Abstract

Phosphoenolpyruvate (PEP) carboxylase (orthophosphate:oxalacetate carboxylase (phosphorylating), EC 4.1.1.31) was purified 19-fold from the obligate chemoautotroph, Thiobacillus thioparus. Michaelis constants for the substrates were found to be 0.44 mM for phosphoenolpyruvate, 0.89 mM for bicarbonate, and 0.37 mM for magnesium, using Tris-HC1, pH 7.3. 1-Aspartate, 1-malate, and orthophosphate were found to be inhibitors of enzyme activity, while acetyl CoA, FDP, GTP, and CDP had no effect. Dioxane greatly stimulated enzyme activity.

摘要

磷酸烯醇式丙酮酸（PEP）羧化酶（正磷酸：草酰乙酸羧化酶（磷酸化），EC 4.1.1.31）从专性化能自养菌硫杆菌中纯化了19倍。使用pH 7.3的Tris-HC1，发现该酶对底物的米氏常数分别为：磷酸烯醇式丙酮酸0.44 mM、碳酸氢盐0.89 mM、镁0.37 mM。发现L-天冬氨酸、L-苹果酸和正磷酸盐是酶活性的抑制剂，而乙酰辅酶A、FDP、GTP和CDP没有影响。二恶烷极大地刺激了酶活性。