Alekseev S B, Mamaev V B, Stepanova L G, Kalinina L I, Andzhaparidze O G
Biokhimiia. 1979 Jul;44(7):1251-5.
The thermal inactivation kinetics of glucose-6-phosphate dehydrogenase during ageing of human diploid cells were studied. It was shown that semi-logarithmic anamorphisms of the thermal inactivation kinetic curves may be presented as a total of two rectilinear sites corresponding to the thermolabile and thermostable fractions of the enzyme. In ageing cells the enzyme stability is decreased as compared to the young ones due to the increase in the amount of the thermolabile fraction. It was also found that despite a certain variability in the process of the cell growth at the 22nd passage the thermal stability of glucose-6-phosphate dehydrogenase is decreased, while the enzyme thermal stability in the cells at the 52nd passage is monotonously increased. Purification of the enzyme from ageing and young human diploid cells results in an increase of the enzyme stability. However, when the enzyme was isolated from young cells, it possessed a higher thermal stability.
研究了人二倍体细胞衰老过程中葡萄糖-6-磷酸脱氢酶的热失活动力学。结果表明，热失活动力学曲线的半对数变形可呈现为总共两个直线部分，分别对应于酶的热不稳定部分和热稳定部分。与年轻细胞相比，衰老细胞中酶的稳定性降低，这是由于热不稳定部分的量增加所致。还发现，尽管在第22代细胞生长过程中存在一定的变异性，但葡萄糖-6-磷酸脱氢酶的热稳定性降低，而第52代细胞中酶的热稳定性则单调增加。从衰老和年轻的人二倍体细胞中纯化该酶会导致酶稳定性增加。然而，当从年轻细胞中分离该酶时，它具有更高的热稳定性。
