离子强度和 pH 值对酵母甲酸脱氢酶热稳定性的影响。

Department of Chemical Enzymology, Faculty of Chemistry, Lomonosov Moscow State University.

Acta Naturae. 2010 Jul;2(2):82-8.

The kinetics of the thermal inactivation of recombinant wild-type formate dehydrogenase from Candida boidinii yeast was studied in the temperature range of 53-61(o)C and pH 6.0, 7.0, and 8.0. It was shown that the loss of the enzyme's activity proceeds via a monomolecular mechanism. Activation parameters ∆Н(-) and ∆S(-) were calculated based on the temperature relations dependence of inactivation rate constants according to the transition state theory. Both parameters are in a range that corresponds to globular protein denaturation processes. Optimal conditions for the stability of the enzyme were high concentrations of the phosphate buffer or of the enzyme substrate sodium formate at pH = 7.0.

研究了毕赤酵母重组野生型甲酸盐脱氢酶在 53-61(o)C 温度范围和 pH 值为 6.0、7.0 和 8.0 时的热失活动力学。结果表明，酶活性的丧失是通过单分子机制进行的。根据过渡态理论，根据失活速率常数与温度关系的依赖关系，计算了激活参数 ∆H(-)和 ∆S(-)。这两个参数的范围与球状蛋白变性过程相对应。在 pH=7.0 时，高浓度的磷酸盐缓冲液或酶底物甲酸钠有利于提高酶的稳定性。