Myosins of secretory tissues.
Myosins of secretory tissues.
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分泌组织的肌球蛋白。
DOI：
10.1083/jcb.77.3.827
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发表时间：
1978-06
影响因子：
7.8
通讯作者：
Kipnis, D M
中科院分区：
文献类型：
--
作者：
Ostlund, R E Jr;Leung, J T;Kipnis, D M
肌球蛋白已从鲶鱼的主要胰岛、猪唾液腺和猪脑垂体中提纯。在分离垂体肌球蛋白时，必须使用蛋白酶抑制剂特雷西洛（FBA Pharmaceuticals，纽约）。分泌组织肌球蛋白与平滑肌肌球蛋白非常相似，具有200，000道尔顿的重链和14，000和19，000道尔顿的轻链。唾液腺肌球蛋白与平滑肌肌球蛋白和成纤维细胞肌球蛋白的抗体发生交叉反应，但不与抗肌球蛋白血清反应。在0.6 M KCl中测得的特定肌球蛋白ATP酶活性存在。与激素颗粒分泌相关的组织中含有大量的这种ATP酶，大鼠胰岛具有大鼠肝脏的4.5倍。激活低离子强度肌球蛋白ATP酶的肌动蛋白不能被证明，尽管足够的肌球蛋白结合到肌肉肌动蛋白和洗脱MgATP。肌球蛋白主要位于细胞质中，细胞分级法测定，并在低离子强度的缓冲液中相当可溶。
Myosin has been purified from the principal pancreatic islet of catfish, hog salivary gland, and hog pituitary. Use of the protease inhibitor Trasylol (FBA Pharmaceuticals, New York) was essential in the isolation of pituitary myosin. Secretory tissue myosins were very similar to smooth muscle myosin, having a heavy chain of 200,000 daltons and light chains of 14,000 and 19,000 daltons. Salivary gland myosin cross-reacted with antibodies directed toward both smooth muscle myosin and fibroblast myosin, but not with antiskeletal muscel myosin serum. The specific myosin ATPase activity measured in 0.6 M KCl was present. Tissues associated with secretion of hormone granules contained substantial amounts of this ATPase, rat pancreatic islets having 4.5 times that of rat liver. Activation of low ionic strength myosin ATPase by actin could not be demonstrated despite adequate binding of the myosin to muscle actin and elution by MgATP. The myosins were located primarily in the cytoplasm as determined by cell fractionation and were quite soluble in buffers of low ionic strength.