Changes in Ion Selectivity Following the Asymmetrical Addition of Charge to the Selectivity Filter of Bacterial Sodium Channels.
Changes in Ion Selectivity Following the Asymmetrical Addition of Charge to the Selectivity Filter of Bacterial Sodium Channels.
复制标题
不对称地向细菌钠通道选择性过滤器添加电荷后离子选择性的变化。
DOI：
10.3390/e22121390
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发表时间：
2020-12-09
期刊：
影响因子：
--
通讯作者：
Guardiani C
中科院分区：
文献类型：
--
作者：
Fedorenko OA;Khovanov IA;Roberts SK;Guardiani C
电压门控钠通道（NaVs）在真核生物中发挥着重要作用，但其特殊的尺寸阻碍了其结构解析。细菌NaV是其真核对应物的简化同源物，但它们作为真核Na+通道模型的用途受到其同源四聚体结构的限制，这与真核NaV的不对称选择性过滤器（SF）不一致。这项工作的目的是模仿真核NaVs的SF工程径向不对称到SF的细菌通道。这一目标是追求两种方法：共表达的不同单体的NaChBac细菌通道，以诱导异源四聚体的随机组装，和串联的四个细菌单体，形成一个多联体，可以通过定点诱变的目标。膜片钳测量和分子动力学模拟表明，SF中额外的门控电荷导致Na+的显着增加和NavMs串联体中Ca 2+电导的适度增加，这与具有最高比例的电荷-5e通道的随机异源四聚体群体的行为一致。因此，我们表明，尽管电荷很重要，但并不是传导和选择性的唯一决定因素，我们创造了新的工具，扩展了细菌通道作为真核生物通道模型的使用。
Voltage-gated sodium channels (NaVs) play fundamental roles in eukaryotes, but their exceptional size hinders their structural resolution. Bacterial NaVs are simplified homologues of their eukaryotic counterparts, but their use as models of eukaryotic Na+ channels is limited by their homotetrameric structure at odds with the asymmetric Selectivity Filter (SF) of eukaryotic NaVs. This work aims at mimicking the SF of eukaryotic NaVs by engineering radial asymmetry into the SF of bacterial channels. This goal was pursued with two approaches: the co-expression of different monomers of the NaChBac bacterial channel to induce the random assembly of heterotetramers, and the concatenation of four bacterial monomers to form a concatemer that can be targeted by site-specific mutagenesis. Patch-clamp measurements and Molecular Dynamics simulations showed that an additional gating charge in the SF leads to a significant increase in Na+ and a modest increase in the Ca2+ conductance in the NavMs concatemer in agreement with the behavior of the population of random heterotetramers with the highest proportion of channels with charge −5e. We thus showed that charge, despite being important, is not the only determinant of conduction and selectivity, and we created new tools extending the use of bacterial channels as models of eukaryotic counterparts.
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影响因子：
16.6
作者：
Bagneris, Claire;DeCaen, Paul G.;Hall, Benjamin A.;Naylor, Claire E.;Clapham, David E.;Kay, Christopher W. M.;Wallace, B. A.
通讯作者：
Wallace, B. A.
DOI：
10.1051/epjnbp/2017003
发表时间：
2017-09-11
期刊：
EPJ NONLINEAR BIOMEDICAL PHYSICS
影响因子：
--
作者：
Kaufman, Igor Kh.;Fedorenko, Olena A.;Eisenberg, Robert S.
通讯作者：
Eisenberg, Robert S.
DOI：
10.1007/s00249-009-0574-2
发表时间：
2010-04-01
影响因子：
2
作者：
Cheng, Ricky C. K.;Tikhonov, Denis B.;Zhorov, Boris S.
通讯作者：
Zhorov, Boris S.
影响因子：
3.3
作者：
Kaufman, I. kh;McClintock, P. V. E.;Eisenberg, R. S.
通讯作者：
Eisenberg, R. S.
影响因子：
3.4
作者：
Guardiani, Carlo;Fedorenko, Olena A.;Roberts, Stephen K.
通讯作者：
Roberts, Stephen K.