The kinetics of increase in chromatin protein content in heated cells: a possible role in cell killing.
The kinetics of increase in chromatin protein content in heated cells: a possible role in cell killing.
复制标题
加热细胞中染色质蛋白含量增加的动力学：在细胞杀伤中可能发挥作用。
作者：
J. R. Roti Roti;K. Henle;R. Winward
从哺乳动物细胞分离的染色质的蛋白质含量在40和48°C之间的温度下加热，相对于对照细胞增加。这种染色质蛋白质含量增加的动力学是通过在40和48°C之间的温度下加热HeLa细胞长达60分钟来定义的。在43°C以上的温度下，这些动力学显示出快速的初始增加速率，其衰减到较慢的极限速率。染色质蛋白质含量的初始增加速率遵循Arrhenius定律，活化焓为86.8 ± 1.4 kcal/mole。在44至48°C之间测定的高血压细胞存活曲线显示细胞杀伤的活化焓为153.8 ± 2.5 kcal/mole。在48°C下，蛋白质增加的活化熵为208.2 cal/mole K，细胞杀伤的活化熵为419.6 cal/mole K。虽然染色质蛋白质含量增加的活化焓和熵约为细胞杀伤的一半，但活化的吉布斯自由能与细胞杀伤的吉布斯自由能相似。
The protein content of chromatin isolated from mammalian cells that are heated at temperatures between 40 and 48°C, is increased relative to that from control cells. The kinetics of this increase in chromatin protein content was defined by heating HeLa cells at temperatures between 40 and 48°C for periods of up to 60 min. At temperatures above 43°C, these kinetics show a rapid initial rate of increase which decays to a slower limiting rate. The initial rate of increase in chromatin protein content obeys the Arrhenius law with an activation enthalpy of 86.8 ± 1.4 kcal/mole. Hyperthermia-cell-survival curves, determined between 44 to 48°C, show an activation enthalpy of 153.8 ± 2.5 kcal/mole for cell killing. At 48°C, the activation entropies are 208.2 cal/mole K for the protein increase and 419.6 cal/mole K for cell killing. Although the activation enthalpy and entropy for the increased protein content of chromatin are about half those for cell killing, the Gibbs free energy of activation is similar for bo...