Solution structure of cardiotoxin V from Naja naja atra.
Solution structure of cardiotoxin V from Naja naja atra.
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DOI：
10.1021/bi00082a026
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发表时间：
1993-08
期刊：
影响因子：
2.9
通讯作者：
A. Singhal;K. Chien;W. Wu;G. Rule
中科院分区：
文献类型：
--
作者：
A. Singhal;K. Chien;W. Wu;G. Rule
蛇毒素是在眼镜蛇科蛇的毒液中发现的小蛋白质。已知这些毒素结合并破坏细胞膜的组织、完整性和功能。大多数研究充分的心脏毒素引起膜电位去极化和/或红细胞溶解。相比之下，来自眼镜蛇的CTX V显示出差的溶血活性，但擅长诱导鞘磷脂囊泡的聚集和融合[Chien等（1991）J.Biol.Chem.266，3252-3259]。为了确定该CTX的独特活性是否归因于其三级结构，通过NMR方法确定CTX V的溶液结构。在这些研究的基础上，这种心脏毒素与该家族的其他成员具有相同的一般拓扑结构，因此其不寻常的性质不会产生于通过溶液NMR方法可检测到的任何总体结构差异。分子动力学计算表明，残基36-50显示协同波动。在序列相似性的基础上，我们假设残基30-34在确定心脏毒素对囊泡融合与裂解的特异性方面是重要的。
Cardiotoxins are small proteins that are found in the venoms of snakes from the Elapidae family. These toxins are known to bind to and disrupt the organization, integrity, and function of the cell membrane. Most of the well-studied cardiotoxins cause depolarization of membrane potentials and/or lysis of red cells. In contrast, CTX V from Naja naja atra displays poor hemolytic activity but is proficient at inducing aggregation and fusion of sphingomyelin vesicles [Chien et al. (1991) J. Biol. Chem. 266, 3252-3259]. To determine whether the unique activity of this CTX is attributable to its tertiary structure, the solution structure of CTX V was determined by NMR methods. On the basis of these studies, this cardiotoxin has the same general topology as other members of the family, and thus its unusual properties do not arise from any gross structural differences that are detectable by solution NMR methods. Molecular dynamics calculations indicate that residues 36-50 show concerted fluctuations. On the basis of sequence similarity, we postulate that residues 30-34 are important in determining the specificity of cardiotoxins for fusion versus lysis of vesicles.