Sharma R K, Desai R, Thompson T R, Wang J H
Can J Biochem. 1978 Jun;56(6):598-604. doi: 10.1139/o78-090.
The recently discovered heat-stable inhibitor protein of the Ca2+-activated cyclic nucleotide phosphodiesterase (Sharma, R. K., Wirch, E. & Warg, J. H. (1978) J. Biol. Chem., in press) has been purified 238 214-fold from bovine brain extract using an affinity column of the modulator protein--Sepharose 4B conjugate. The purified sample appears to be homogeneous as judged by sodium dodecyl sulphate (SDS) gel electrophoresis. The protein band has a mobility corresponding to that of a polypeptide of molecular weight 68 000. Since the heat-stable inhibitor protein has a molecular weight of 70 000 under nondenaturing conditions, it suggests that it is a monomeric protein. The protein has no inhibitory activity toward the cAMP-dependent protein kinase or protein phosphatase. The purified sample has been tested for various enzyme activities which include ATPase, GTPase, cAMP phosphodiesterase, cGMP phosphodiesterase, 5'-nucleotidase, and protein kinase. None of these activities are exhibited by the purified sample.
最近发现的钙激活环核苷酸磷酸二酯酶的热稳定抑制蛋白（夏尔马，R.K.，维尔奇，E.和瓦尔格，J.H.（1978年）《生物化学杂志》，即将发表）已通过使用调节蛋白-琼脂糖4B偶联物的亲和柱从牛脑提取物中纯化了238214倍。通过十二烷基硫酸钠（SDS）凝胶电泳判断，纯化后的样品似乎是纯一的。蛋白带的迁移率与分子量为68000的多肽相对应。由于热稳定抑制蛋白在非变性条件下的分子量为70000，这表明它是一种单体蛋白。该蛋白对环磷酸腺苷依赖性蛋白激酶或蛋白磷酸酶没有抑制活性。已对纯化后的样品进行了多种酶活性测试，包括ATP酶、GTP酶、环磷酸腺苷磷酸二酯酶、环磷酸鸟苷磷酸二酯酶、5'-核苷酸酶和蛋白激酶。纯化后的样品没有表现出这些活性中的任何一种。
