A calcium- and pH-regulated protein from Dictyostelium discoideum that cross-links actin filaments
A calcium- and pH-regulated protein from Dictyostelium discoideum that cross-links actin filaments
复制标题
来自盘基网柄菌的钙和 pH 调节蛋白，可交联肌动蛋白丝
DOI：
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发表时间：
1982
影响因子：
7.8
通讯作者：
Maryanne Vahey
中科院分区：
文献类型：
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作者：
J. Condeelis;Maryanne Vahey
我们从盘基网柄菌阿米巴中纯化了一种肌动蛋白结合蛋白，我们称之为 95,000 道尔顿蛋白 (95K)。这种蛋白质呈杆状，在电子显微镜下长约 40 nm，包含两个各自大小为 95,000 道尔顿的亚基，并与肌动蛋白丝交联。通过使用落球粘度计、奥斯特瓦尔德粘度计和电子显微镜证明了交联活性。交联活性在 0.1 microM Ca++ 和 pH 6.8 时最佳，但在生理范围内较高的 Ca++ 和 pH 水平下会逐渐受到抑制。半最大抑制分别发生在 1.6 microM 游离 Ca++ 和 pH 7.3 时。沉降实验表明，Ca++ 和 pH 值升高会抑制 95K 与 F-肌动蛋白的结合，这解释了交联活性的丧失。电子显微镜表明，在最佳交联条件下，95K 蛋白束会形成肌动蛋白丝，并且这种成束会受到 microM Ca++ 的抑制。在所使用的任何溶液条件下的任何各种测定中均未观察到肌动蛋白丝被 95K 切断。因此，95K 蛋白是一种棒状、二聚体、Ca++ 和 pH 调节的肌动蛋白结合蛋白，可交联但不会切断肌动蛋白丝。
We have purified an actin binding protein from amebas of Dictyostelium discoideum which we call 95,000-dalton protein (95K). This protein is rod shaped, approximately 40 nm long in the electron microscope, contains two subunits measuring 95,000 daltons each, and cross-links actin filaments. Cross-linking activity was demonstrated by using falling-ball viscometry, Ostwald viscometry, and electron microscopy. Cross-linking activity is optimal at 0.1 microM Ca++ and pH 6.8, but is progressively inhibited at higher Ca++ and pH levels over a physiological range. Half-maximal inhibition occurs at 1.6 microM free Ca++ and pH 7.3, respectively. Sedimentation experiments demonstrate that elevated Ca++ and pH inhibit the binding of 95K to F-actin which explains the loss of cross-linking activity. Electron microscopy demonstrates that under optimal conditions for cross-linking, 95K protein bundles actin filaments and that this bundling is inhibited by microM Ca++. Severing of actin filaments by 95K was not observed in any of the various assays under any of the solution conditions used. Hence, 95K protein is a rod-shaped, dimeric, Ca++- and pH-regulated actin binding protein that cross-links but does not sever actin filaments.
从棘阿米巴中纯化钙敏感肌动蛋白凝胶蛋白。
DOI：
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发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Pollard,TD
通讯作者：
Pollard,TD