期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：5
页码：1860-1864
DOI：10.1073/pnas.74.5.1860
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Microtubule protein from porcine cerebrum was fractionate into pure tubulin and microtubule-associated proteins by chromatography on phosphocellulose. In agreement with previous studies, pure tubulin does not form microtubules to a significant extent at 37 degrees in normal assembly buffers, which are characterized by a low concentration of Mg2+ ions. If, however, the Mg2+ concentration is raised to approximately 10 mM, rapid and extensive self-assembly of pure tubulin into microtubules is observed, provided the tubulin concentration is above 2.5 mg/ml. At a protein concentration of 3 mg/ml, the lag period is 1.5 min and the assembly process is virtually complete after 6 min at 37 degrees. These microtubules are like normal microtubules--sensitive to calcium ions, colchicine, and low temperature.
