INTERFERENCE OF GTP HYDROLYSIS IN THE MECHANISM OF MICROTUBULE ASSEMBLY - AN EXPERIMENTAL-STUDY
INTERFERENCE OF GTP HYDROLYSIS IN THE MECHANISM OF MICROTUBULE ASSEMBLY - AN EXPERIMENTAL-STUDY
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DOI：
10.1073/pnas.81.3.771
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发表时间：
1984-01-01
期刊：
影响因子：
--
通讯作者：
CHEN, YD
中科院分区：
文献类型：
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作者：
CARLIER, MF;HILL, TL;CHEN, YD
根据先前发表的模型和理论，研究了 GTP 水解对微管组装机制的干扰。稀释实验的结果表明，在临界浓度以下，微管解聚速度比可逆聚合模型预期的要快。通量与微管蛋白浓度的实验图在临界浓度处表现出斜率不连续性，与理论一致。通过蒙特卡罗方法计算的理论点可以定性地拟合数据。微管这种特殊动态行为的结果是，分别在低于和高于临界浓度时测得的微管蛋白解离和结合速率常数的比率不能产生临界浓度的真实值。微管末端 GTP 的存在对于维持聚合物的稳定性是必要的。
The interference of GTP hydrolysis in the mechanism of microtubule assembly was studied, following the model and theory previously published. Results from dilution experiments show that microtubules depolymerize faster below the critical concentration than expected with a reversible polymerization model. The experimental plot of flux vs. tubulin concentration exhibits a slope discontinuity at the critical concentration, in agreement with the theory. Theoretical points calculated by the Monte Carlo method can be fitted qualitatively to the data. A consequence of this peculiar dynamic behavior of microtubules is that the ratio of tubulin dissociation and association rate constants measured, respectively, below and above the critical concentration does not yield the true value of the critical concentration. The presence of GTP at microtubule ends is necessary to maintain the stability of the polymer.