Identification of G actin-binding proteins in rat tissues using a gel overlay technique.
Identification of G actin-binding proteins in rat tissues using a gel overlay technique.
复制标题
使用凝胶覆盖技术鉴定大鼠组织中的 G 肌动蛋白结合蛋白。
DOI：
10.1016/0014-4827(83)90324-5
复制
发表时间：
1983
影响因子：
3.7
通讯作者：
Bryan,J
中科院分区：
文献类型：
--
作者：
Snabes,MC;Boyd3rd,AE;Bryan,J
肌动蛋白结合蛋白测定在各种组织中使用125碘-肌动蛋白覆盖程序。已鉴定出四种主要的G肌动蛋白结合蛋白，其分子量分别为90 000、65 000、58 000和40 000 Mr。90 K蛋白存在于所有组织中，并以钙敏感的方式结合标记的肌动蛋白，在Ca 2+存在下结合增加3-4倍。对Ca ~（2+）不敏感的58 K和65 K蛋白的分布变化较大。这些蛋白质在不同组织中以不同的比例存在。125 I-肌动蛋白与所有四种肌动蛋白结合蛋白的结合是特异性的，并且可以通过用未标记的肌动蛋白预孵育凝胶来置换。肌动蛋白与这些蛋白质的相互作用似乎并不涉及离子力，因为结合并没有通过改变盐浓度而减弱。骨骼肌糖酵解酶、透镜晶体蛋白和组蛋白也结合125 I-肌动蛋白。这种结合不能通过与未标记的肌动蛋白预孵育来取代，并且推测是非特异性的。用~（125）I-actin比较了两种高纯度的肌动蛋白结合蛋白90 K人血小板蛋白和绒毛蛋白的钙敏感性。血小板90 K蛋白在低于10− 7 M游离钙时与肌动蛋白结合，但在低于10− 6 M游离钙时不会与绒毛蛋白结合。这些肌动蛋白结合蛋白的普遍存在是清楚的，我们得出结论，在所有这些组织中的钙敏感90 K肌动蛋白结合蛋白是相同的血小板蛋白。
Actin-binding proteins were assayed in various tissues using an125I-actin overlay procedure. Four major G actin-binding proteins of 90 000, 65 000, 58 000 and 40 000Mrhave been identified. The 90K protein is present in all tissues and binds labelled actin in a calcium-sensitive manner with binding increasing 3–4-fold in the presence of Ca2+. The distribution of the 58K and 65K protein which are not Ca2+-sensitive was more variable. These proteins were present in different ratios in different tissues.125I-actin binding to all four actin-binding proteins is specific and can be displaced by preincubation of the gels with unlabelled actin. The interaction of actin with these proteins does not appear to involve ionic forces, since binding is not diminished by varying the salt concentration. Skeletal muscle glycolytic enzymes, the lens crystallins and the histones also bind125I-actin. This binding cannot be displaced by preincubation with unlabelled actin and is presumably non-specific. The calcium sensitivity of two highly purified actin-binding proteins, the 90K human platelet protein and villin was compared using125I-actin. The platelet 90K protein binds actin at less than 10−7M free calcium, but detectable binding to villin does not occur below 10−6M free calcium. The ubiquity of these actin-binding proteins is clear and we conclude that the calcium-sensitive 90K actin-binding protein in all of these tissues is the same as the platelet protein.