荧光探针1.8-ANS对尖吻蝮(AGKISTRODON ACUTUS)蛇毒出血毒素1疏水区的研究

尖吻蝮蛇毒出血毒素1(A2H-1)和荧光疏水探针1.8-ANS结合,其激发峰在370nm,发射峰在470nm,A2H-1存在着可探测的疏水区,ANS不抑制A2H-1的出血活性。每个A2H-1分子统计结合1.42个AaH分子,AaH-1-ANS的解离常数;Kd=1.53×10-5M。 AaH-1-ANS复合物的荧光强度对pH,温度,EDTA等条件的变化敏感,并相应引起出血活性的改变。AaH-1的Trp荧光能部分地转移到结合的ANS上,转移效率为0.523,说明Trp可能处于AaH-1分子表面的凹陷疏水区。

BINDING OF 1-ANILINO-8-NAPHTHALENESULFONATE TO HYDROPHOBIC REGION OF HEMORRHAGIN-1 FROM AGKISTRODON ACUTUSVENOM

When the hydrophobic probe 1-anilino-8-naphthalenesulfonate (1.8 ANS) is bound to Hemorrhagin-1 (A2H-1) from A.Acutus venom, its excitation and emission maxima are at 370nm and 470nm respectively. There is a hydrophobic region in A2H-1. Kd=1.53×10-5M, n=1.43. 1.8ANS does not inhibit hemorrhagic activity of A2H-1.Intensity of fluorescence emission of AaH-l-ANS is sensitive to the PH, EDTA, and temperature. The hemorrhagic activity of A2H-1 in these conditions shows corresponding changes.Energy transfer from Trp residus of A2H-1 to the bound ANS is observed. The efficency of energy transfer is 0.523. The Trp residus may be situated in hydrophobic region.Change of comformation of hydrophobic region of A2H-1 results in the change of hemorrhagic activity.