Microtubule-associated proteins and the flexibility of microtubules.
Microtubule-associated proteins and the flexibility of microtubules.
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DOI：
10.1021/bi00041a014
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发表时间：
1995-10
期刊：
影响因子：
2.9
通讯作者：
J. Kurz;Robley C. Williams
中科院分区：
文献类型：
--
作者：
J. Kurz;Robley C. Williams
进行实验以了解微管相关蛋白（MAP）与微管的结合是否改变微管的柔性。通过两种已建立的技术在体外测量柔韧性。第一个采用的弯曲的微管在缓冲液流的测量;第二个涉及的微管的形状的随机热波动的重复测量。从纯化的微管蛋白制备的微管和从含有饱和浓度的从牛脑分离的MAP的微管蛋白制备的微管获得类似的值。当在37 ℃和pH 6.9下通过流动技术测量时，发现纯微管蛋白微管的持久长度为8.4 +/- 2.2 mm，而含有MAP的微管的持久长度为9.4 +/- 2.7 mm，彼此没有显著差异。当在相同条件下通过热波动技术测量时，获得6.2 +/- 0.8和6.5 +/-0.8mm的值，同样彼此没有显著差异。结果表明，在体外的天然微管的MAP的结合有很少或没有影响其灵活性。在体内观察到的MAP诱导的细胞骨架的影响可能是由于其他原因，如微管束的形成。
Experiments were conducted to learn whether the binding of microtubule-associated proteins (MAPs) to microtubules alters the flexibility of the microtubules. Flexibility was measured in vitro by two established techniques. The first employed measurement of the bending of the microtubule in a flow of buffer; the second involved repeated measurement of random thermal fluctuations in the microtubule's shape. Similar values were obtained from microtubules prepared from purified tubulin and those prepared from microtubule protein containing saturating concentrations of MAPs isolated from bovine brain. When measured by the flow technique at 37 degrees C and pH 6.9, the persistence length of pure tubulin microtubules was found to be 8.4 +/- 2.2 mm and that of MAP-containing microtubules was 9.4 +/- 2.7 mm, not significantly different from each other. When measured by the thermal fluctuation technique under identical conditions, values of 6.2 +/- 0.8 and 6.5 +/- 0.8 mm were obtained, again not significantly different from each other. The results show that the binding of MAPs to native microtubules in vitro has little or no effect on their flexibility. MAP-induced effects on the cytoskeleton observed in vivo are likely to be due to other causes, such as formation of microtubule bundles.