尖吻蝮蛇蛇毒出血毒素Ⅲ的荧光光谱

FLUORESCENCE SPECTRA OF HEMORRHAGIN Ⅲ FROM THE SNAKE VENOM OF AGKISTRODON ACUTUS

皖南尖吻蝮蛇蛇毒经分离和纯化得到出血毒素Ⅲ（ＡａＨⅢ），质谱测定分子量为２３，２８４．４±０．１。实验表明，Ｔｒｐ残基较大程度位于ＡａＨⅢ分子的疏水区。十二烷基磺酸钠（ＳＤＳ）和盐酸胍的加入使ＡａＨⅢ的分子构象发生变化，导致分子内色氨酸（Ｔｒｐ）残基的荧光淬灭。盐酸胍的加入使Ｔｒｐ残基的荧光发射峰位明显红移，表明位于ＡａＨⅢ分子较疏水环境的Ｔｒｐ残基相对外露。我们还就酸度、ＥＤＴＡ和金属离子对ＡａＨⅢ分子内Ｔｒｐ残基荧光光谱的影响进行了研究和讨论。

Hemorrhagin Ⅲ(AaH Ⅲ) was separated and purified from the crude snake venom of Agkistrodon acutus, and its molecule weight was determined accurately to be 23,284 4±0 1 by LDI1700 MALDI TOF MS Emission spectra of AaH Ⅲ showed that Trp residues were located by a great degree in the hydrophobic area Addition of SDS and guanidine HCl led to change of the molecular conformation of AaH Ⅲ, and caused the fluorescence quenching of Trp residues The red shifted emission band of AaH Ⅲ after adding guanidine HCl showed that Trp residues exposed in polar solvents The effects of pH, EDTA and metal ions on the fluorescence spectra of AaH Ⅲ were also investigated