Control of ion selectivity in potassium channels by electrostatic and dynamic properties of carbonyl ligands

@article{Noskov2004ControlOI,
  title={Control of ion selectivity in potassium channels by electrostatic and dynamic properties of carbonyl ligands},
  author={Sergei Yu. Noskov and Simon Bern{\`e}che and Beno{\^i}t Roux},
  journal={Nature},
  year={2004},
  volume={431},
  pages={830-834}
}
Potassium channels are essential for maintaining a normal ionic balance across cell membranes. Central to this function is the ability of such channels to support transmembrane ion conduction at nearly diffusion-limited rates while discriminating for K+ over Na+ by more than a thousand-fold. This selectivity arises because the transfer of the K+ ion into the channel pore is energetically favoured, a feature commonly attributed to a structurally precise fit between the K+ ion and carbonyl groups… Expand
The predominant role of coordination number in potassium channel selectivity.
TLDR
It is demonstrated that the number of carbonyl oxygen atoms that surround permeating ions is the most important factor in determining ion selectivity rather than the size of the pore or the strength of the coordinating dipoles. Expand
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TLDR
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TLDR
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TLDR
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TLDR
It is found that Na(+) ion presents in a mostly hydrated state inside the wide pore of the selectivity filter of the sodium channel, in sharp contrast to the nearly fully dehydrated state for K(+) ions in potassium channels. Expand
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TLDR
A simple theoretical analysis of K+ and Na+ complexation with water in the context of simplified binding site models and bulk solution reveals that water molecules and carbonyl groups can both provide K+ selective environments if equivalent constraints are imposed on the coordination number of the complex. Expand
Mechanism of ion permeation and selectivity in a voltage gated sodium channel.
TLDR
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Mechanism of potassium-channel selectivity revealed by Na+ and Li+ binding sites within the KcsA pore
TLDR
It is proposed that selective permeation from the intracellular side primarily results from a large energy barrier blocking filter entry for Na+ and Li+ in the presence of K+, not from a difference of binding affinity between ions. Expand
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TLDR
The role of I131, and potentially other structural elements outside the SF, in controlling ion selectivity are illuminated, by suggesting that the physical interaction of these elements with the SF contributes to the relative stability of the constrained K+-induced SF configuration versus nonselective dilated conformations. Expand
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TLDR
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TLDR
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