一种钙/钙调蛋白依赖性的蛇毒磷脂酶A_2

A Calcium/Calmodulin Dependent Phospholipase A_2 Obtained from Chinese Agkistrodon blomhoffii Ussurensis Venom

分别研究了钙离子和三价稀土离子对白眉蝮蛇 (Agkistrodon blomhoffii Ussurensis)蛇毒磷脂酶 A2(PLA2 )活性的影响以及钙调蛋白对它的激活作用 .实验结果表明 ,PLA2 的活性对钙离子表现出依赖性 ,钙调蛋白能够激活该蛇毒 PLA2 ,钙调蛋白的拮抗剂三氟甲基吩噻嗪 (Trifluoperazine)能够完全抑制它对 PLA2的激活作用 .三价稀土离子 La3+、Eu3+、Dy3+、Yb3+对该 PLA2 的活性表现出抑制作用 ,其中离子半径较大的La3+和 Eu3+对酶活的抑制程度要小于半径较小的 Dy3+和 Yb3+.

The effects of calcium ion and rare earth ions on the activity of a phospholipase A 2(PLA 2) obtained from Chinese Agkistrodon blomhoffii Ussurensis venom have been investigated. The results indicated that the activity of snake venom PLA 2 is dependent on the concentration of calcium ion. Calmodulin(CAM), a calcium dependent regulator can also stimulate the activity of PLA 2. La 3+ ,Eu 3+ ,Dy 3+ ,Yb 3+ showed different levels of inhibitory effects on the PLA 2s activity mostly due to difference in ion radius. The relative activity of PLA 2 inhibited by La 3+ or Yb 3+ at the concentration of 13 5 μmol/L was 63 5% and 31 8%, respectively.