一种来自三带盾尾蝎毒液的新型毒素，是新的α-KTX亚家族的首个成员。

A novel toxin from the venom of the scorpion Tityus trivittatus, is the first member of a new alpha-KTX subfamily.

作者信息

Abdel-Mottaleb Yousra, Coronas Fredy V, de Roodt Adolfo R, Possani Lourival D, Tytgat Jan

机构信息

Laboratory of Toxicology, University of Leuven, Onderwijs and Navorsing II, Herestraat 49, Postbus 922, 3000 Leuven, Belgium.

出版信息

FEBS Lett. 2006 Jan 23;580(2):592-6. doi: 10.1016/j.febslet.2005.12.073. Epub 2006 Jan 4.

DOI:10.1016/j.febslet.2005.12.073

PMID:16405970

Abstract

The first example of a new sub-family of toxins (alpha-KTx20.1) from the scorpion Tityus trivittatus was purified, sequenced and characterized physiologically. It has 29 amino acid residues, three disulfide bridges assumed to adopt the cysteine-stabilized alpha/beta scaffold with a pI value of 8.98. The sequence identities with all the other known alpha-KTx are less than 40%. Its effects were verified using seven different cloned K(+) channels (vertebrate Kv1.1-1.5, Shaker IR and hERG) expressed in Xenopus leavis oocytes. The toxin-induced effects show large differences among the different K(+) channels and a preference towards Kv1.3 (EC50=7.9+/-1.4 nM).

摘要

从三带盾尾蝎中分离出了一个新的毒素亚家族（α-KTx20.1），并对其进行了纯化、测序及生理特性鉴定。它含有29个氨基酸残基，有三个二硫键，假定采用半胱氨酸稳定的α/β支架结构，其等电点为8.98。与所有其他已知的α-KTx的序列同一性小于40%。利用非洲爪蟾卵母细胞中表达的七种不同的克隆钾离子通道（脊椎动物Kv1.1 - 1.5、Shaker IR和hERG）验证了该毒素的作用。毒素诱导的效应在不同的钾离子通道之间表现出很大差异，并且对Kv1.3有偏好性（半数有效浓度EC50 = 7.9±1.4 nM）。