Nishida E, Maekawa S, Sakai H
J Biochem. 1983 Apr;93(4):1021-6. doi: 10.1093/oxfordjournals.jbchem.a134225.
The kinetics and thermodynamics of microtubule assembly were studied using outer doublet tubulin isolated from starfish sperm. Purified tubulin was gel-filtered just prior to the experiments. The self-polymerization process was found to be characterized by a lag followed by a growth phase that did not show a single first-order decay reaction. This suggested that the nucleation and elongation steps are not completely separate. The maximal rate of polymerization and the reciprocal of the duration of lag time increased approximately in proportion to the third and second powers of tubulin concentration above the critical concentration, respectively. Measurement of temperature dependence of the critical concentration gave a linear van't Hoff plot with delta H degree = 13.5 kcal/mol and delta S degree = 69 e.u.
利用从海星精子中分离出的外双联微管蛋白研究了微管组装的动力学和热力学。在实验前，将纯化的微管蛋白进行凝胶过滤。发现自聚合过程的特征是有一个延迟期，随后是一个生长阶段，该生长阶段未表现出单一的一级衰变反应。这表明成核和延伸步骤并非完全分开。聚合的最大速率和延迟时间的倒数分别与高于临界浓度的微管蛋白浓度的三次方和二次方大致成比例增加。对临界浓度的温度依赖性进行测量，得到了线性范特霍夫图，其中ΔH° = 13.5千卡/摩尔，ΔS° = 69熵单位。
