Zinc modulation of proton currents in a new voltage-gated proton channel suggests a mechanism of inhibition.
Zinc modulation of proton currents in a new voltage-gated proton channel suggests a mechanism of inhibition.
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DOI：
10.1111/febs.15291
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发表时间：
2020-11
期刊：
影响因子：
--
通讯作者：
Musset B
中科院分区：
文献类型：
--
作者：
Chaves G;Bungert-Plümke S;Franzen A;Mahorivska I;Musset B
HV 1电压门控质子（HV 1）通道是细胞质子挤出机制的关键组成部分，对于吞噬细胞呼吸爆发期间的电荷补偿至关重要。HV 1的最佳生理抑制剂是Zn 2+。据报道，外部施加的ZnCl 2大幅减少质子电流记录在智人，褐家鼠，小家鼠，Oryctolagus cuniculus，蛙，Hatlaspersa，玻璃海鞘，Coccolithus pelagicus，Emiliania huxleyi，Danio rerio，Helisoma trivolvis和Lingulodinium polyedrum，但具有相当大的物种变异性。在这里，我们报告了Zn 2+和Cd 2+对来自Nicoletia phytophila的HV 1（NpHV 1）的影响。我们在潜在的Zn 2+配位位点引入突变，并在不同的胞外pH下测量Zn 2+抑制，Zn 2+浓度高达1000 μm。Zn 2+抑制NpHV 1定量的激活时间常数和正移的电导-电压曲线的减慢。用组氨酸（D145 H）取代S3-S4环中的天冬氨酸，增强了激活动力学的减慢和电压-电导曲线的移动，使得Zn 2+抑制与人类通道的抑制非常相似。组氨酸在S3-S4接头中配位Zn 2+方面比天冬氨酸有效得多。一个简单的Hodgkin Huxley模型的NpHV 1表明，如果它被锌或镉抑制，开放率下降。极限斜率测量和高分辨率透明天然凝胶电泳（hrCNE）证实NpHV 1作为二聚体发挥作用。这些数据支持锌在二聚体而不是单体之间配位的假设。锌配位位点可能是药物开发的潜在目标。锌被许多酶结合或协调。然而，参与锌配位的氨基酸在蛋白质之间是不同的。锌对昆虫电压门控质子通道（NpHV 1）的抑制表明在二聚体界面处结合。锌与质子竞争，并在非导电状态下将两个单体互锁。抑制机制是非静电结合，而不是通过通道的质子渗透途径的阻塞。
The HV1 voltage‐gated proton (HV1) channel is a key component of the cellular proton extrusion machinery and is pivotal for charge compensation during the respiratory burst of phagocytes. The best‐described physiological inhibitor of HV1 is Zn2+. Externally applied ZnCl2 drastically reduces proton currents reportedly recorded in Homo sapiens, Rattus norvegicus, Mus musculus, Oryctolagus cuniculus, Rana esculenta, Helix aspersa, Ciona intestinalis, Coccolithus pelagicus, Emiliania huxleyi, Danio rerio, Helisoma trivolvis, and Lingulodinium polyedrum, but with considerable species variability. Here, we report the effects of Zn2+ and Cd2+ on HV1 from Nicoletia phytophila, NpHV1. We introduced mutations at potential Zn2+ coordination sites and measured Zn2+ inhibition in different extracellular pH, with Zn2+ concentrations up to 1000 μm. Zn2+ inhibition in NpHV1 was quantified by the slowing of the activation time constant and a positive shift of the conductance–voltage curve. Replacing aspartate in the S3‐S4 loop with histidine (D145H) enhanced both the slowing of activation kinetics and the shift in the voltage–conductance curve, such that Zn2+ inhibition closely resembled that of the human channel. Histidine is much more effective than aspartate in coordinating Zn2+ in the S3‐S4 linker. A simple Hodgkin Huxley model of NpHV1 suggests a decrease in the opening rate if it is inhibited by zinc or cadmium. Limiting slope measurements and high‐resolution clear native gel electrophoresis (hrCNE) confirmed that NpHV1 functions as a dimer. The data support the hypothesis that zinc is coordinated in between the dimer instead of the monomer. Zinc coordination sites may be potential targets for drug development. Zinc is bound or coordinated by numerous enzymes. However, the amino acids, involved in zinc coordination, differ between the proteins. Zinc inhibition of the insect voltage‐gated proton channel (NpHV1) suggests binding at the dimer interface. Zinc competes with protons and is interlocking both monomers in a nonconductive state. The mechanism of inhibition is a nonelectrostatic binding and not a block of the proton permeation pathway through the channel.
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影响因子：
33.6
作者：
DeCoursey TE
通讯作者：
DeCoursey TE
影响因子：
30.5
作者：
通讯作者：
--
DOI：
10.1085/jgp.201511456
发表时间：
2015-11
期刊：
The Journal of general physiology
影响因子：
--
作者：
Cherny VV;Morgan D;Musset B;Chaves G;Smith SM;DeCoursey TE
通讯作者：
DeCoursey TE
影响因子：
2.6
作者：
Cho DY;Hajighasemi M;Hwang PH;Illek B;Fischer H
通讯作者：
Fischer H
影响因子：
64.8
作者：
Alabi, AbdulRasheed A.;Bahamonde, Maria Isabel;Swartz, Kenton J.
通讯作者：
Swartz, Kenton J.