Maleimide conjugates of saxitoxin as covalent inhibitors of voltage-gated sodium channels.
Maleimide conjugates of saxitoxin as covalent inhibitors of voltage-gated sodium channels.
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DOI：
10.1021/ja4019644
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发表时间：
2013-07
影响因子：
15
通讯作者：
W. Parsons;J. Du Bois
中科院分区：
文献类型：
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作者：
W. Parsons;J. Du Bois
（+）-石房蛤毒素是一种天然存在的胍类毒物，是电压门控钠离子通道（NaVs）的有效、选择性和可逆抑制剂。这种带有半胱氨酸反应性马来酰亚胺基团的毒素的修饰形式可通过全合成获得，并且发现其不可逆地抑制重组表达的野生型钠通道和海马神经细胞中的钠离子电导。我们的研究结果支持了一种共价蛋白质修饰的机制，其中毒素结合到通道孔之前，亲核氨基酸的马来酰亚胺烷基化。还发现第二代马来酰亚胺-毒素缀合物，其包括生物正交反应基团，不可逆地阻断通道功能;此类化合物具有作为用于活细胞成像和/或蛋白质组学实验的NaV的选择性标记的试剂的潜力。
(+)-Saxitoxin, a naturally occurring guanidinium poison, functions as a potent, selective, and reversible inhibitor of voltage-gated sodium ion channels (NaVs). Modified forms of this toxin bearing cysteine-reactive maleimide groups are available through total synthesis and are found to irreversibly inhibit sodium ion conductance in recombinantly expressed wild-type sodium channels and in hippocampal nerve cells. Our findings support a mechanism for covalent protein modification in which toxin binding to the channel pore precedes maleimide alkylation of a nucleophilic amino acid. Second-generation maleimide-toxin conjugates, which include bioorthogonal reactive groups, are also found to block channel function irreversibly; such compounds have potential as reagents for selective labeling of NaVs for live cell imaging and/or proteomics experiments.