The Rockefeller University, 1230 York Avenue, New York, New York 10021.
Proc Natl Acad Sci U S A. 1980 Apr;77(4):1912-6. doi: 10.1073/pnas.77.4.1912.
Calmodulin, a multifunctional calcium-modulated protein, has been isolated from spinach leaf tissue and from spinach leaf messenger RNA translation products. The translation protein and the spinach leaf protein have been partially characterized and compared to vertebrate calmodulins. Spinach leaf calmodulin will quantitatively activate bovine brain phosphodiesterase and will undergo a calcium-dependent shift in electrophoretic mobility similar to that of bovine brain calmodulin. In the presence of Ca(2+) the spinach and brain proteins comigrate, but in the presence of chelators they do not. A polyadenylylated RNA fraction has been isolated from spinach leaf tissue and translated in a wheat germ cell-free translation system. The calmodulin synthesized in vitro has been isolated by using calcium-dependent affinity chromatography on phenothiazine-Sepharose conjugates. The translation protein comigrates with spinach calmodulin during polyacrylamide gel electrophoresis whether in the presence or the absence of Ca(2+). The translation protein also undergoes a calcium-dependent mobility shift identical to that of spinach calmodulin. Amino acid analysis of the translation calmodulin indicates that it does not contain N(epsilon)-trimethyllysine, an amino acid residue that is characteristic of all calmodulins previously examined. These studies suggest that N(epsilon)-trimethyllysine is not required for the calcium-dependent interaction of calmodulin with phenothiazines and indicate the potential utility of phenothiazine-Sepharose conjugates as affinity-based adsorbents in biological and biochemical investigations.
钙调蛋白是一种多功能的钙调节蛋白，已从菠菜叶片组织和菠菜叶片信使 RNA 翻译产物中分离出来。该翻译蛋白和菠菜叶片蛋白已被部分表征，并与脊椎动物钙调蛋白进行了比较。菠菜叶片钙调蛋白将定量激活牛脑磷酸二酯酶，并经历类似于牛脑钙调蛋白的钙离子依赖性电泳迁移率变化。在 Ca(2+)存在下，菠菜和脑蛋白共迁移，但在螯合剂存在下则不迁移。已从菠菜叶片组织中分离出多聚腺苷酸化 RNA 片段，并在小麦胚细胞无细胞翻译系统中进行翻译。使用苯并噻嗪-Sepharose 缀合物上的钙离子依赖性亲和层析从体外合成的钙调蛋白。在有无 Ca(2+)的情况下，翻译蛋白在聚丙烯酰胺凝胶电泳中与菠菜钙调蛋白共迁移。翻译蛋白还经历与菠菜钙调蛋白相同的钙离子依赖性迁移率变化。翻译钙调蛋白的氨基酸分析表明，它不含有 N(epsilon)-三甲基赖氨酸，这是以前检查过的所有钙调蛋白的特征氨基酸残基。这些研究表明，N(epsilon)-三甲基赖氨酸不是钙调蛋白与苯并噻嗪相互作用所必需的，并表明苯并噻嗪-Sepharose 缀合物作为基于亲和的吸附剂在生物和生化研究中的潜在用途。
