Kishimoto A, Takai Y, Mori T, Kikkawa U, Nishizuka Y
J Biol Chem. 1980 Mar 25;255(6):2273-6.
Ca2+-activated, phospholipid-dependent protein kinase from various mammalian tissues (Takai, Y., Kishimoto, A., Iwasa, Y., Kawahara, Y., Mori, T., and Nishizuka, Y (1979) J. Biol. Chem. 254, 3692-3695) was greatly stimulated by the addition of diacylglycerol at less than 5% (w/w) the concentration of phospholipid. This stimulation was due to an increase in the apparent affinity of enzyme for phospholipid and to a concomitant decrease in the Ka value for Ca2+ from about 1 x 10(-4) M to the micromolar range. Diacylglycerol alone showed little or no effect on enzymatic activity over a wide range of Ca2+ concentrations. This effect was greatest for diacylglycerol which contained unsaturated fatty acid at least at position 2. The active diacylglycerols so far tested included diolein, dilinolein, diarachidonin, 1-stearoyl-2-oleoyl diglyceride, and 1-stearoyl-2-linoleoyl diglyceride. In contrast, diacylglycerols containing saturated fatty acids such as dipalmitin and distearin were far less effective. Triacyl- and monoacylglycerols were totally ineffective, irrespective of the fatty acyl moieties. Cholesterol and free fatty acids were also ineffective. Based on these observations, a possible coupling is proposed between the protein kinase activation and phosphatidylinositol turnover which can be provoked by various extracellular messengers.
来自各种哺乳动物组织的钙激活的、磷脂依赖性蛋白激酶（高井洋、岸本明、岩佐洋、川原洋、森田、西冢泰（1979年）《生物化学杂志》254卷，3692 - 3695页）在添加二酰基甘油时，当二酰基甘油浓度低于磷脂浓度的5%（w/w）时会受到极大刺激。这种刺激是由于酶对磷脂的表观亲和力增加以及伴随的钙离子解离常数（Ka）值从约1×10⁻⁴M降至微摩尔范围。在广泛的钙离子浓度范围内，单独的二酰基甘油对酶活性几乎没有影响。对于至少在2位含有不饱和脂肪酸的二酰基甘油，这种影响最大。目前测试的活性二酰基甘油包括二油精、二亚油精、二花生四烯酸甘油酯、1 - 硬脂酰 - 2 - 油酰甘油和1 - 硬脂酰 - 2 - 亚油酰甘油。相比之下，含有饱和脂肪酸的二酰基甘油，如二棕榈酸甘油酯和二硬脂酸甘油酯，效果要差得多。三酰基甘油和单酰基甘油无论其脂肪酰基部分如何都完全无效。胆固醇和游离脂肪酸也无效。基于这些观察结果，提出了蛋白激酶激活与磷脂酰肌醇周转之间可能存在的偶联关系，而磷脂酰肌醇周转可由各种细胞外信使引发。
