Kapoor C L, Chader G J
Biochem Biophys Res Commun. 1984 Aug 16;122(3):1397-403. doi: 10.1016/0006-291x(84)91246-4.
A calcium phospholipid-dependent protein kinase (C-kinase) activity was detected in the soluble fraction of rod outer segments (ROS) of the bovine retina. The enzyme required calcium, phosphatidylserine (PS) and diacylglycerol for maximal activity. In the presence of calcium and PS, C-kinase endogenously phosphorylated proteins with molecular weights of 95,000, 91,000, 31,000, 21,000, 19,000, 18,000, 16,000, 14,000 and 11,000. Addition of diolein in the reaction mixture further enhanced the endogenous phosphorylation of these proteins. Retinal was found to inhibit the phosphorylation of endogenous proteins by C-kinase in a concentration dependent manner. Half-maximal inhibition of enzyme activity was obtained at a retinal concentration of about 12 microM. These results suggest that calcium, phospholipids and the C-kinase enzyme may play an important role in the functional regulation of rod photoreceptors and, with retinal, perhaps in the visual process as well.
在牛视网膜视杆外段（ROS）的可溶性部分检测到一种钙磷脂依赖性蛋白激酶（C激酶）活性。该酶需要钙、磷脂酰丝氨酸（PS）和二酰基甘油才能达到最大活性。在钙和PS存在的情况下，C激酶会使分子量为95,000、91,000、31,000、21,000、19,000、18,000、16,000、14,000和11,000的蛋白质发生内源性磷酸化。在反应混合物中加入二油精可进一步增强这些蛋白质的内源性磷酸化。发现视黄醛以浓度依赖性方式抑制C激酶对内源性蛋白质的磷酸化。在视黄醛浓度约为12微摩尔时，酶活性受到半数最大抑制。这些结果表明，钙、磷脂和C激酶酶可能在视杆光感受器的功能调节中起重要作用，并且与视黄醛一起，可能在视觉过程中也起重要作用。
