皖南尖吻蝮蛇出血毒素生物学活性与圆二色性关系的研究  

Studies on the Relationship Between the Biological Activities and the Circular Dichroism of South Anhui Dienagkistrodon Acutus Hemorrhagins

作　　者：朱学勇[1,2] 朱中良[1,2] 龚为民 滕脉坤[1,2] 牛立文[1,2] 

机构地区：[1]中国科学技术大学结构生物学青年实验室 [2]中国科学院生物物理所生物大分子国家重点实验室

出　　处：《生物化学与生物物理学报》1997年第2期163-169,共7页

基　　金：中国科学院"八五"重大基础研究项目;中国科学院生物大分子国家重点实验室基金;国家教委博士点基金;跨世纪优秀人才计划

摘　　要：用远紫外ＣＤ谱研究了皖南尖吻蝮蛇蛇毒３个出血毒素ＡａＨⅠ、ＡａＨⅢ和ＡａＨⅣ的溶液构象，ＡａＨⅠ的α螺旋、β折叠、β转角和无规卷曲的含量分别为２５．８％、１２．７％、２６．８％和３４．７％；ＡａＨⅢ的二级结构含量分别为２３．９％、２０．６％、２３．７％和３１．８％；而ＡａＨⅣ分别为１８．２％、３１．０％、１７．２％和３３．６％。当ｐＨ小于４．０或ｐＨ大于１１．０时，３种出血毒素α螺旋减少而β折叠增多，同时３种出血毒素的酪蛋白水解活性显著下降。ＥＤＴＡ抑制酪蛋白水解活性，表明３种出血毒素均是金属蛋白酶。ＥＤＴＡ、Ｃｕ２＋、Ｚｎ２＋、Ｃａ２＋和Ｍｇ２＋能改变３种出血毒素的二级结构，并影响酪蛋白水解活性。The solution conformations of three hemorrhagic toxins, designated as AaHⅠ, AaHⅢ and AaHⅣ, from South Anhui dienagkistrodon acutus have been studied by CD spectra. The secondary structure of AaHⅠconsisted of 25.8% α helix, 12.7% β sheet and 26.8% β turns, together with 34.7% random coil. For AaHⅢ,the secondary structure contents were 23.9%, 20.6%,23.7% and 31.8%, and for AaHⅣ they were 18.2%, 31.0%, 17.2 and 33.6%, respectively. When pH was lower than 4.0 or higher than 11.0 , the α helix decreased but β sheet increased, meanwhile, the caseinolytic activities of the three toxins decreased. The activities could be inhibited by EDTA, which indicated that all the three toxins were all metalloproteinases. EDTA, Cu 2+ , Zn 2+ , Ca 2+ and Mg 2+ could change the secondary structures and play an important role in caseinolytic activities.

关 键 词：尖吻蝮蛇 出血毒素 圆二色性 生物学活性 

分 类 号：Q959.620.6[生物学—动物学]