A bottom-up approach to the ion recognition mechanism of K+ channels from laser spectroscopy of hydrated partial peptide?alkali metal ion complexes
A bottom-up approach to the ion recognition mechanism of K+ channels from laser spectroscopy of hydrated partial peptide?alkali metal ion complexes
复制标题
水合部分肽碱金属离子配合物激光光谱中 K 通道离子识别机制的自下而上方法
DOI：
10.1039/d2cp01667b
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发表时间：
2022
影响因子：
3.3
通讯作者：
Fujii Masaaki
中科院分区：
文献类型：
--
作者：
Suzuki Yukina;Hirata Keisuke;Lisy James M.;Ishiuchi Shun-ichi;Fujii Masaaki
K+通道允许K+选择性渗透，但不允许生理上丰富的Na+，几乎以扩散极限速率渗透。K+通道的传导机制仍然存在争议，实验和计算研究支持两种不同的传导机制：通道内有水或没有水。在这里，我们采用自下而上的方法对K+通道模型肽的水合碱金属配合物Ac-Tyr-NHMe进行研究，以表征在分子水平上控制K+通道选择性的金属-肽、金属-水和水-肽相互作用。扩展到碱金属离子系列和温度依赖性研究（接近生理值）都揭示了离子配合物光谱特征中透性和非透性离子的明显差异。此外，通过比较非水合配合物和水合配合物，讨论了水合作用对K+通道的影响。
K+ channels allow selective permeation of K+, but not physiologically abundant Na+, at almost diffusion limit rates. The conduction mechanism of K+ channels is still controversial, with experimental and computation studies supporting two distinct conduction mechanisms: either with or without water inside the channel. Here, we employ a bottom-up approach on hydrated alkali metal complexes of a model peptide of K+ channels, Ac-Tyr-NHMe, to characterize metal–peptide, metal–water, and water–peptide interactions that govern the selectivity of K+ channels at a molecular level. Both the extension to the series of alkali metal ions and to temperature-dependent studies (approaching physiological values) have revealed the clear difference between permeable and non-permeable ions in the spectral features of the ion complexes. Furthermore, the impact of hydration is discussed in relation to the K+ channels by comparisons of the non-hydrated and hydrated complexes.