Bryan J, Wilson L
Proc Natl Acad Sci U S A. 1971 Aug;68(8):1762-6. doi: 10.1073/pnas.68.8.1762.
Colchicine-binding protein, considered to be microtubule protein, was purified from chick embryo brain by column chromatography in one step on DEAE-Sephadex. The active colchicine-binding unit is a dimer, MW 115,000 +/- 5000, which is composed of two nonidentical monomeric units. The two subunits are separable by urea-acrylamide gel electrophoresis after they have been reduced and acetylated. Sodium dodecyl sulfate-acrylamide gel electrophoresis indicates that the subunits both have molecular weights of 55,000 +/- 2000. The amino-acid compositions of the two subunits showed statistically significant differences in six amino-acid residues. These results indicate that colchicine-sensitive cytoplasmic microtubules are heteropolymers.
秋水仙碱结合蛋白，被认为是微管蛋白，通过在DEAE - 葡聚糖凝胶上一步柱层析从鸡胚脑中纯化得到。活性秋水仙碱结合单元是一种二聚体，分子量为115,000±5000，由两个不相同的单体单元组成。这两个亚基在还原和乙酰化后可通过尿素 - 丙烯酰胺凝胶电泳分离。十二烷基硫酸钠 - 丙烯酰胺凝胶电泳表明这两个亚基的分子量均为55,000±2000。这两个亚基的氨基酸组成在六个氨基酸残基上显示出统计学上的显著差异。这些结果表明对秋水仙碱敏感的细胞质微管是异源聚合物。
