Gaskin F, Kress Y
J Biol Chem. 1977 Oct 10;252(19):6918-24.
Zinc ion-induced assembly of tubulin was followed using electron microscopy and turbidimetric measurements. A scheme utilizing repeated cycles of assembly and disassembly was used to prepare tubulin and microtubule-associated proteins (MAPs) (Shelanski, M. L., Gaskin, F., and Cantor, C. R. (1973) Proc. Natl. Acad. Sci. U. S. A. 70, 765-768). Tubulin was further purified by phosphocellulose chromatography to remove the MAPs (Weingarten, M., Lockwood, A. H., Hwo, S-Y, and Kirschner, M. W. (1975) Proc. Natl. Acad. Sci. U. S. A. 72, 1858-1862). In tubulin preparations containing MAPs and added GTP, Zn2+-induced sheets of 15 to 60 protofilaments oriented in parallel. In the absence of MAPs and/or added GTP, Zn2+ induced the formation of sheets which wrapped quite specifically and serial sections were often consistent with a tubular structure of approximately 220 nm. The assembly of recycled tubulin + GTP and 0 to 1 mM Zn2+ was analyzed by A350 as a function of time at 30 degrees. The greater the concentration of Zn2+, the shorter the lag time, the faster the rate after the lag, and the greater the plateau value of A350. Although turbidimetric measurements can be used to quantitate microtubules, they are not quantitative for Zn2+-induced sheets.
利用电子显微镜和比浊法测量来追踪锌离子诱导的微管蛋白组装过程。采用一种利用组装和拆卸重复循环的方案来制备微管蛋白和微管相关蛋白（MAPs）（谢兰斯基，M. L.，加斯金，F.，和坎托，C. R.（1973年）《美国国家科学院院刊》70，765 - 768）。通过磷酸纤维素色谱法进一步纯化微管蛋白以去除MAPs（温加滕，M.，洛克伍德，A. H.，许，S - Y，和基尔希纳，M. W.（1975年）《美国国家科学院院刊》72，1858 - 1862）。在含有MAPs并添加了GTP的微管蛋白制剂中，锌离子诱导形成15至60条原纤维平行排列的片层。在没有MAPs和/或添加GTP的情况下，锌离子诱导形成的片层会非常特异性地包裹起来，连续切片通常与大约220纳米的管状结构一致。回收的微管蛋白 + GTP与0至1 mM锌离子的组装过程在30摄氏度下通过A350随时间的变化进行分析。锌离子浓度越高，滞后时间越短，滞后后的速率越快，A350的平台值越大。尽管比浊法测量可用于定量微管，但对于锌离子诱导的片层而言，它们并非定量的。
