Kinetic analysis of the M2 proton conduction of the influenza virus.
Kinetic analysis of the M2 proton conduction of the influenza virus.
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DOI：
10.1021/ja108458u
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发表时间：
2010-12-22
影响因子：
15
通讯作者：
Chou JJ
中科院分区：
文献类型：
--
作者：
Pielak RM;Chou JJ
流感病毒的M2蛋白形成病毒复制所必需的质子选择性通道。该通道具有缓慢的传导速率，但对质子具有近乎完美的选择性。已经提出了许多模型来解释质子传导机制的基础上全细胞通道记录和分子动力学模拟，但详细的动力学分析的通道活动尚未进行。我们使用灵敏且可重现的脂质体质子通量测定法获得了M2及其多种变体的详细传导与pH测量值。质子传输遵循具有两个饱和步骤的Michaelis-Menten样动力学：一个在pH ~5.5下的假饱和，和另一个在pH ~4下的完全饱和。该机制的核心是孔衬His 37和Trp 41。核磁共振测量表明，组氨酸和色氨酸一致行动，以运输质子的浓度梯度。从动力学数据中得出的表观Km的对数与组氨酸pKa密切匹配，并与Trp 41门的化学位移扰动相关，表明组氨酸质子化和通道门的打开是同步事件。最后，诱变和结构分析确定了影响传导速率的关键残基。
M2 protein of the flu virus forms a proton selective channel that is necessary for viral replication. The channel has slow rate of conduction, but attains near perfect selectivity for proton. Many models have been proposed to explain the mechanism of proton conduction based on whole cell channel recordings and molecular dynamics simulations, but a detailed kinetic analysis of the channel activity has yet been performed. We obtained detailed conduction vs. pH measurements for M2 and a number of its variants using a sensitive and reproducible liposome proton flux assay. The proton transport follows Michaelis-Menten-like kinetics with two saturation steps: one pseudosaturation at pH ~5.5, and another full saturation at pH ~4. The heart of the mechanism is the pore-lining His37 and Trp41. NMR measurements suggest that histidine and tryptophan act in unison to transport protons down the concentration gradient. The log of apparent Km derived from the kinetics data matches closely to the histidine pKa and correlates with chemical shift perturbation of the Trp41 gate, indicating that histidine protonation and opening of the channel gate are synchronized events. Finally, mutagenesis and structural analysis identified key residues that affect the rate of conduction.
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影响因子：
4.8
作者：
Tang, YJ;Zaitseva, F;Pinto, LH
通讯作者：
Pinto, LH
影响因子：
5.5
作者：
Chizhmakov, IV;Geraghty, FM;Hay, AJ
通讯作者：
Hay, AJ
来自固态NMR的流感M2质子通道中质子传导和门控的机制。
DOI：
10.1126/science.1191714
发表时间：
2010-10-22
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Hu F;Luo W;Hong M
通讯作者：
Hong M
影响因子：
16.8
作者：
通讯作者：
--
DOI：
10.1016/j.bbrc.2010.09.008
发表时间：
2010-10-08
影响因子：
3.1
作者：
Pielak RM;Chou JJ
通讯作者：
Chou JJ