Wilkins J A, Lin S
Cell. 1982 Jan;28(1):83-90. doi: 10.1016/0092-8674(82)90377-4.
Immunofluorescence and microinjection experiments have shown that vinculin (molecular weight 130,000) is localized at adhesion plaques of fibroblasts spread on a solid substrate. We found that this protein affects actin filament assembly and interactions in vitro at substoichiometric levels. Vinculin inhibits the rate of actin polymerization under conditions that limit nuclei formation, indicating an effect on the filament elongation step of the reaction. Vinculin also reduces actin filament--filament interactions measured with a low-shear viscometer. Scatchard plot analysis of the binding of 3H-labeled vinculin to actin filaments showed that there is one high-affinity binding site (dissociation constant=20 nM) for every 1,500-2,000 actin monomers. These results suggested that vinculin interacts with a specific site located at the growing ends of actin filaments in a cytochalasin-like manner, a property consistent with its proposed function as a linkage protein between filaments and the plasma membranes.
免疫荧光和显微注射实验表明，纽蛋白（分子量130,000）定位于铺展在固体基质上的成纤维细胞的黏着斑处。我们发现，这种蛋白质在亚化学计量水平下影响体外肌动蛋白丝的组装和相互作用。在限制核形成的条件下，纽蛋白抑制肌动蛋白聚合的速率，表明其对反应的丝延长步骤有影响。纽蛋白还降低了用低剪切粘度计测量的肌动蛋白丝-丝相互作用。对3H标记的纽蛋白与肌动蛋白丝结合的Scatchard图分析表明，每1500-2000个肌动蛋白单体有一个高亲和力结合位点（解离常数=20 nM）。这些结果表明，纽蛋白以类似于细胞松弛素的方式与位于肌动蛋白丝生长末端的特定位点相互作用，这一特性与其作为丝与质膜之间连接蛋白的假定功能一致。
