Quantitative analysis of tubulin and microtubule compartments in isolated rat hepatocytes.
Quantitative analysis of tubulin and microtubule compartments in isolated rat hepatocytes.
复制标题
分离的大鼠肝细胞中微管蛋白和微管室的定量分析。
DOI：
10.1083/jcb.75.3.731
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发表时间：
1977-12
影响因子：
7.8
通讯作者：
Miller, M D
中科院分区：
文献类型：
--
作者：
Reaven, E P;Cheng, Y;Miller, M D
结合形态学和生物化学的方法已被用来确定和定量分离的肝细胞中的微管和微管蛋白。通过与放射性标记的秋水仙素特异性高亲和力结合来估计微管蛋白的总可溶性池。Scatchard分析的数据确定了两个群体的结合位点：高亲和力低容量的网站类似微管蛋白和低亲和力高容量的网站，认为代表非特异性秋水仙素结合位点。这些研究的数据表明，微管蛋白占细胞可溶性蛋白质的1%，每微克可溶性肝细胞蛋白质中存在9.0 × 10（-14）微管蛋白二聚体，平均肝细胞含有3.1 × 10（7）微管蛋白二聚体。我们的计算表明，如果完全组装，这些量的微管蛋白将形成长度为1.9厘米的微管。然而，体视学测量表明，平均肝细胞胞质区室中微管的实际长度仅为0.28 cm。因此，这些实验表明，只有15%的吸收后大鼠的肝细胞中可用的微管蛋白组装在微管的形式。
A combined morphometric and biochemical approach has been used to identify and quantitate microtubules and tubulin in isolated hepatocytes. The total soluble pool of microtubule protein was estimated by specific high affinity binding to radiolabeled colchicine. Scatchard analysis of the data identified two populations of binding sites: high affinity-low capacity sites resembling tubulin and low affinity-high capacity sites believed to represent nonspecific colchicine-binding sites. Data from these studies indicate that tubulin represents 1% of the soluble protein of the cell, that 9.0 X 10(-14) dimers of tubulin are present per microgram soluble hepatocyte protein, and that the average hepatocyte contains 3.1 X 10(7) tubulin dimers. Our calculations suggest that this amount of tubulin would form a microtubule 1.9 cm in length if totally assembled. However, stereological measurements indicate that the actual length of microtubules in the cytosolic compartment of the average hepatocyte is only 0.28 cm. Thus, these experiments suggest that only 15% of the available tubulin in hepatocytes of postabsorptive rats is assembled in the form of microtubules.