Watterson D M, Harrelson W G, Keller P M, Sharief F, Vanaman T C
J Biol Chem. 1976 Aug 10;251(15):4501-13.
Results of studies of the Ca2+-dependent protein modulator of 3':5'-cyclic nucleotide phosphodiesterase isolated from bovine brain are presented which show its structural similarity to the Ca2+-binding subunit of muscle troponin. Both proteins have blocked NH2 termini, similar and characteristic ultraviolet absorption spectra, similar Ca2+-binding properties, very similar amino acid compositions, and co-migrate on sodium dodecyl sulfate-polyacrylamide gels. The primary structures of selected tryptic peptides isolated from bovine brain modulator protein are similar or identical with regions of the primary sequences of rabbit skeletal muscle and bovine cardiac muscle troponin C. Bovine brain modulator protein contains and unidentified ninhydrin-positive basic compound not found in muscle troponin C. An improved procedure is presented which yields 40 to 70 mg of modulator protein per kg of bovine brain.
本文展示了从牛脑中分离出的3':5'-环核苷酸磷酸二酯酶的钙依赖性蛋白调节剂的研究结果，这些结果表明它与肌肉肌钙蛋白的钙结合亚基在结构上相似。这两种蛋白质都有封闭的氨基末端、相似且具有特征性的紫外吸收光谱、相似的钙结合特性、非常相似的氨基酸组成，并且在十二烷基硫酸钠-聚丙烯酰胺凝胶上共同迁移。从牛脑调节剂蛋白中分离出的选定胰蛋白酶肽的一级结构与兔骨骼肌和牛心肌肌钙蛋白C的一级序列区域相似或相同。牛脑调节剂蛋白含有一种在肌肉肌钙蛋白C中未发现的未鉴定的茚三酮阳性碱性化合物。本文介绍了一种改进的方法，每千克牛脑可产生40至70毫克的调节剂蛋白。
