瑞香素在体外对蛋白激酶A和蛋白激酶C活力的影响

Effects of Daphnetin on Activities of Protein Kinase A and Protein Kinase C in Vitro

部分纯化的蛋白激酶A和蛋白激酶C，在体外分别与瑞香素温育。瑞香素浓度达0．56×10-8mol／L时，显著抑制Ⅱ型蛋白激酶A的活力，大于0．56×10－5mol／L时，抑制Ⅰ型蛋白激酶A的活力，而高至0．56×10-4mol／L时，才能抑制蛋白激酶C的活力。结果表明，瑞香素对Ⅱ型蛋白激酶A有较高的特异抑制作用。

Daphnetin, isolated from Daphne koreane Nakai, has been reported to dilate blood vesse ls, inhibit thrombosis and have antiinflammatory effect. In this study, type Ⅰ and type Ⅱ protcin kinase A partially purified from rat skeletal muscle and protein kinase C from rat brain were incubated with varying concentrations of daphnetin. Type Ⅱ protein kinase A was siguificantly inhibited by daphnetin at the concentration of 0.0056μmol/L, while type Ⅰ protein kinase A and protein kinasc C were inhibitcd at the concentrations of 5.6μmol／L and 56 μmol/L, respectively. The results indicated that daphnetin might be used as a specific inhibitor of type Ⅱ protein kinase A