Single amino acid substitutions in κ-conotoxin PVIIA disrupt interaction with the Shaker K+ channel
Single amino acid substitutions in κ-conotoxin PVIIA disrupt interaction with the Shaker K+ channel
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DOI：
10.1074/jbc.c900990199
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发表时间：
2000-08-11
影响因子：
4.8
通讯作者：
Terlau, H
中科院分区：
文献类型：
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作者：
Jacobsen, RB;Koch, ED;Terlau, H
K-芋螺毒素PVILA（kappa-PVIIA），一种具有三个二硫键交联的27-氨基酸肽，分离自Conus purpurascens的毒液，是第一种显示抑制Shaker K+通道的芋螺肽（Terlau，H.，Shon，K.，Grilley，M.，斯托克，里，Stuhmer，W.，和Olivera，B. M.（1996）Nature 381，148-151）。最近，两个小组使用NMR独立地确定了kappa-PVIIA的溶液结构;尽管报道的结构相似，但提出了肽与Shaker通道相互作用的两个互斥模型。我们进行了kappa-PVIIA的结构/功能分析，两组都假定所有氨基酸都被丙氨酸取代为关键残基。我们的数据与Menez及其同事开发的临界二元模型一致（Dauplais，M.，Lecoq，A.，宋杰，Cotton，J.，Jamin，N.，Gilquin，B.，Roumestand角，维塔角，de Medeiros，C.，Rowan，E. G.，Harvey，A. L.，和Menez，A.（1997）J.Biol.Chem.272，4802-4809）。在κ-PVIIA的情况下，如Savarin等人所预测的，Lys（7）和Phe（9）对于活性是必需的（Savarin，P.，Guenneugues，M.，Gilquin，B.，Lamthanh，H.，加斯帕里尼，S.，Zinn-Justin，S.，和Menez，A.（1998）Biochemistry 37，5407-5416）;这些工作者还正确地预测了Lys的重要作用（25）。因此，尽管K-芋螺毒素PVIIA与来自其他有毒动物的与电压门控K+通道相互作用的多肽毒素没有明显的序列同源性，但在不同的KC通道多肽拮抗剂中可能存在会聚的功能特征。
K-Conotoxin PVILA (kappa-PVIIA), a 27-amino acid peptide with three disulfide cross-links, isolated from the venom of Conus purpurascens, is the first conopeptide shown to inhibit the Shaker K+ channel (Terlau, H., Shon, K., Grilley, M., Stocker, Ri., Stuhmer, W., and Olivera, B. M. (1996) Nature 381, 148-151). Recently, two groups independently determined the solution structure for kappa-PVIIA using NMR; although the structures reported were similar, two mutually exclusive models for the interaction of the peptide with the Shaker channel were proposed. We carried out a structure/function analysis of kappa-PVIIA, with alanine substitutions for all amino acids postulated to be key residues by both groups. Our data are consistent with the critical dyad model developed by Menez and co-workers (Dauplais, M., Lecoq, A., Song, J., Cotton, J., Jamin, N., Gilquin, B., Roumestand, C., Vita, C., de Medeiros, C., Rowan, E. G., Harvey, A. L., and Menez, A. (1997) J. Biol. Chem. 272, 4802-4809) for polypeptide antagonists of KC channels. In the case of kappa-PVIIA, Lys(7) and Phe(9) are essential for activity as predicted by Savarin et al. (Savarin, P., Guenneugues, M., Gilquin, B., Lamthanh, H., Gasparini, S., Zinn-Justin, S., and Menez, A. (1998) Biochemistry 37, 5407-5416); these workers also correctly predicted an important role for Lys(25). Thus, although K-conotoxin PVIIA has no obvious sequence homology to polypeptide toxins from other venomous animals that interact with voltage-gated K+ channels, there may be convergent functional features in diverse KC channel polypeptide antagonists.