Itano N, Hatano S
Department of Molecular Biology, Faculty of Science, Nagoya University, Aichi, Japan.
Cell Motil Cytoskeleton. 1991;19(4):244-54. doi: 10.1002/cm.970190403.
An F-actin bundling protein was isolated and purified from plasmodium of Physarum polycephalum. The F-actin bundling protein in Physarum extract was passed through a DEAE-cellulose column. After the protein in the fraction was treated with 6 M urea, it was purified by gel filtration on Sephacryl S-300 HR followed by chromatography on CM-Toyopearl (cation exchange) in the presence of 6 M urea. The purified protein gave a single band on SDS-PAGE, and the molecular weight was estimated to be 52,000. This F-actin bundling protein is referred to as the 52 kDa protein. Interestingly, the 52 kDa protein also induced bundling of microtubules. The formation of F-actin and microtubule bundles was Ca(2+)-insensitive, but depended on the salt concentration. Each bundle formed at NaCl concentrations less than 0.1 M. The 52 kDa protein cross-reacted with monoclonal antibody raised against a HeLa 55 kDa protein (an F-actin bundling protein from HeLa cells) (Yamashiro-Matsumura and Matsumura: J. Biol. Chem. 260:5087-5097, 1985). When the 52 kDa protein was added to a mixture of actin filaments and microtubules, co-bundles composed of both filaments formed. This is the first reported example in which an F-actin bundling protein induced co-bundling of actin filaments and microtubules.
从多头绒泡菌的疟原虫中分离并纯化出一种F-肌动蛋白成束蛋白。多头绒泡菌提取物中的F-肌动蛋白成束蛋白通过DEAE-纤维素柱。将该级分中的蛋白质用6M尿素处理后，先在Sephacryl S-300 HR上进行凝胶过滤，然后在6M尿素存在下在CM-Toyopearl（阳离子交换）上进行层析以进行纯化。纯化后的蛋白质在SDS-PAGE上呈现单一条带，估计分子量为52,000。这种F-肌动蛋白成束蛋白被称为52kDa蛋白。有趣的是，52kDa蛋白还能诱导微管成束。F-肌动蛋白和微管束的形成对Ca(2+)不敏感，但取决于盐浓度。在NaCl浓度低于0.1M时形成每一束。52kDa蛋白与针对HeLa 55kDa蛋白（一种来自HeLa细胞的F-肌动蛋白成束蛋白）产生的单克隆抗体发生交叉反应（Yamashiro-Matsumura和Matsumura：《生物化学杂志》260:5087-5097，1985）。当将52kDa蛋白添加到肌动蛋白丝和微管的混合物中时，由两种丝组成的共束形成。这是首次报道的一个F-肌动蛋白成束蛋白诱导肌动蛋白丝和微管共束的例子。
