Olamendi-Portugal Timoteo, García Blanca Inés, López-González Ignacio, Van Der Walt Jurg, Dyason Karin, Ulens Chris, Tytgat Jan, Felix Ricardo, Darszon Alberto, Possani Lourival D
Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Apartado Postal 510-3 Cuernavaca 62210, Mexico.
Biochem Biophys Res Commun. 2002 Dec 13;299(4):562-8. doi: 10.1016/s0006-291x(02)02706-7.
This report describes the isolation, primary structure determination, and functional characterization of two similar toxins from the scorpion Parabuthus granulatus named kurtoxin-like I and II (KLI and KLII, respectively). KLII from P. granulatus is identical to kurtoxin from Parabuthus transvaalicus (a 63 amino-acid long toxin) whereas KLI is a new peptide containing 62 amino acid residues closely packed by four disulfide bridges with a molecular mass of 7244. Functional assays showed that both toxins, KLI and kurtoxin from P. granulatus, potently inhibit native voltage-gated T-type Ca(2+) channel activity in mouse male germ cells. In addition, KLI was shown to significantly affect the gating mechanisms of recombinant Na(+) channels and weakly block alpha(1)3.3Ca(V) channels expressed in Xenopus oocytes. KLI and kurtoxin from P. granulatus represent new probes to study the role of ion channels in germ cells, as well as in cardiac and neural tissue.
本报告描述了从粒状肥尾蝎中分离出的两种相似毒素——类库毒素I和II（分别为KLI和KLII）的分离过程、一级结构测定及功能特性。粒状肥尾蝎的KLII与德兰士瓦肥尾蝎的库毒素相同（一种由63个氨基酸组成的毒素），而KLI是一种新的肽，含有62个氨基酸残基，由四个二硫键紧密连接，分子量为7244。功能分析表明，粒状肥尾蝎的KLI和库毒素均能有效抑制小鼠雄性生殖细胞中天然电压门控T型Ca(2+)通道的活性。此外，KLI被证明能显著影响重组Na(+)通道的门控机制，并微弱阻断非洲爪蟾卵母细胞中表达的α(1)3.3Ca(V)通道。粒状肥尾蝎的KLI和库毒素是研究离子通道在生殖细胞以及心脏和神经组织中作用的新探针。
