Thompson M P, Piazza G J, Brower D P, Bingham E W, Farrell H M
Eastern Regional Research Center, US Department of Agriculture, Philadelphia, PA 19118.
J Dairy Sci. 1987 Aug;70(8):1551-6. doi: 10.3168/jds.S0022-0302(87)80182-0.
Bovine mammary gland calmodulin, purified by conventional fractionation procedures, was compared with similarly purified bovine brain calmodulin. Affinity chromatography on W-7 agarose of the crude fractions from mammary gland and brain yielded pure proteins containing one trimethyllysine residue per 16,800 daltons with essentially identical amino acid compositions. Kinetic parameters of these two proteins with respect to their ability to activate phosphodiesterase were determined. The constants for half maximum activation were .39 and .44 nM for bovine brain and bovine mammary gland calmodulins, respectively; both proteins gave similar maximum velocities. Based on the amino acid composition and kinetic data, it is concluded that the two proteins are essentially identical.
通过传统分级分离程序纯化得到的牛乳腺钙调蛋白，与同样纯化的牛脑钙调蛋白进行了比较。对乳腺和脑的粗分级分在W-7琼脂糖上进行亲和层析，得到了每16,800道尔顿含有一个三甲基赖氨酸残基且氨基酸组成基本相同的纯蛋白。测定了这两种蛋白激活磷酸二酯酶能力的动力学参数。牛脑和牛乳腺钙调蛋白的半最大激活常数分别为0.39和0.44 nM；两种蛋白的最大速度相似。基于氨基酸组成和动力学数据，得出这两种蛋白基本相同的结论。
