Lee J C, Tweedy N, Timasheff S N
Biochemistry. 1978 Jul 11;17(14):2783-90. doi: 10.1021/bi00607a013.
A comparative study has been carried out of the ability to reconstitute into microtubules of tubulins prepared by the Weisenberg and the cycle procedures. It was found that further purification of cycle tubulin by phosphocellulose chromatography made its ability to polymerize identical with that of Weisenberg tubulin. By adding to either tubulin the isolated proteins which copurify with tubulin in the cycle prodecure, it is possible to reduce their critical concentrations of microtubule formation to a value identical with that of cycle tubulin. It was demonstrated quantitatively that the effect of these nontubulin proteins could be mimicked by a variety of polycationic molecules, the most effective one being poly(L-lysine). A possible mechanism is described by which growing microtubules could be stabilized by subsequent addition of the nontubulin proteins. The conclusion is drawn that, at present, it is not known whether the proteins which copurify with tubulin are specific components of the microtubule system, or simply artefactually coprecipitated impurities.
对通过韦森堡法和循环法制备的微管蛋白重新组装成微管的能力进行了一项比较研究。结果发现，通过磷酸纤维素色谱法对循环微管蛋白进一步纯化，使其聚合能力与韦森堡微管蛋白相同。通过向任何一种微管蛋白中添加在循环过程中与微管蛋白共纯化的分离蛋白，可以将它们形成微管的临界浓度降低到与循环微管蛋白相同的值。定量证明，这些非微管蛋白的作用可以被多种聚阳离子分子模拟，其中最有效的是聚（L-赖氨酸）。描述了一种可能的机制，通过该机制，生长的微管可以通过随后添加非微管蛋白而得到稳定。得出的结论是，目前尚不清楚与微管蛋白共纯化的蛋白质是微管系统的特定成分，还是仅仅是人为共沉淀的杂质。
