Isolation of microtubule protein from chicken erythrocytes and determination of the critical concentration for tubulin polymerization in vitro and in vivo.
Isolation of microtubule protein from chicken erythrocytes and determination of the critical concentration for tubulin polymerization in vitro and in vivo.
复制标题
从鸡红细胞中分离微管蛋白并确定体外和体内微管蛋白聚合的临界浓度。
DOI：
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发表时间：
1983
影响因子：
4.8
通讯作者：
Kathleen T. Wallis
中科院分区：
文献类型：
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作者：
Douglas B. Murphy;Kathleen T. Wallis
从有核鸡红细胞中分离的微管蛋白的组成和组装特性进行了研究，以确定其在微管束称为边缘带的意义。1)该蛋白质含有大于95%的微管蛋白，具有少量的tau多肽，并且没有高分子量多肽。2)微管组装在体外在37摄氏度的特点是低水平的成核，尽管丰富的环低聚物在5摄氏度，如所示的长滞后时间，缓慢的组装速率，和微管的两倍长的大脑微管在相同的条件下组装。3)通过放射免疫分析和十二烷基硫酸钠凝胶分析，我们确定，0.6%的红细胞蛋白是微管蛋白，其中四分之三是在一个不可提取的形式，并与微管束和细胞皮质。根据这些值，总微管蛋白和微管蛋白二聚体亚基的体内浓度分别为2.4和0.7 mg/ml。0.7 mg/ml的值接近于体外红细胞微管蛋白临界浓度0.1-0.6 mg/ml的值范围，表明微管蛋白在体外和体内的组装性质相似。
Microtubule protein isolated from nucleated chicken erythrocytes was examined with respect to composition and assembly properties to determine its significance in a microtubule bundle called the marginal band. 1) The protein contains greater than 95% tubulin with small amounts of tau polypeptides and no high molecular weight polypeptides. 2) Microtubule assembly in vitro at 37 degrees C is characterized by low levels of nucleation, despite an abundance of ring oligomers at 5 degrees C, as indicated by long lag times, slow assembly rates, and microtubules that are twice as long as brain microtubules assembled under the same conditions. 3) By radioimmunoassay and sodium dodecyl sulfate gel analysis we determined that 0.6% of erythrocyte protein is tubulin of which three-quarters is in a nonextractable form and is associated with the microtubule bundle and the cell cortex. From these values the in vivo concentrations of total tubulin and tubulin dimer subunits are 2.4 and 0.7 mg/ml, respectively. The value of 0.7 mg/ml is close to the range of values of 0.1-0.6 mg/ml for the critical concentration of erythrocyte microtubule protein in vitro, suggesting that the assembly properties of tubulin in vitro and in vivo are similar.