Markina V L, Eremin A N, Metelitsa D I
Biofizika. 1985 Nov-Dec;30(6):971-6.
Over the range 20-52 degrees C thermal inactivation of malate dehydrogenase (MDH) was studied with the aim of well grounded choice of its stabilization ways. The process was described by the pseudofirst order rate constants, kin, dependent on enzyme concentration. The rate constant of enzyme inactivation at the "infinite" dilution in general form equals 1.40 X 10(27) X exp (-43 000/RT) s-1, whereas at high enzyme concentration it is 1.26 X 10(8) X exp (-17 700/RT) s-1. The limiting step of the MDH inactivation is the enzyme dissociation into its subunits. In the concentrated enzyme solution a protein association is accompanied by its stabilization. The methods of characterization of oligomeric proteins dissociative inactivation are discussed.
为了合理选择苹果酸脱氢酶（MDH）的稳定方法，研究了其在20至52摄氏度范围内的热失活情况。该过程由依赖于酶浓度的准一级速率常数kin描述。在“无限”稀释时酶失活的速率常数一般形式为1.40×10(27)×exp(-43000/RT)s-1，而在高酶浓度下为1.26×10(8)×exp(-17700/RT)s-1。MDH失活的限速步骤是酶解离成其亚基。在浓缩酶溶液中，蛋白质缔合伴随着其稳定性增加。讨论了寡聚蛋白质解离失活的表征方法。
