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Targeted molecular dynamics simulation of the closing of Kv1.2 potassium channel |
Received:March 04, 2009 |
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DOI:10.7511/jslx20094003 |
KeyWord:potassium channel gating protein molecular dynamics simulation Kv1.2 KcsA |
Author | Institution |
钟文宇 |
南京航空航天大学 纳米科学研究所, 南京 |
郭万林 |
南京航空航天大学 纳米科学研究所, 南京 |
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Abstract: |
Potassium channels are membrane proteins which can open or close an ion conducting pore to control the K+flux across the membrane. The Kv1.2 structure, determined in an open conformation, is the only structure of potassium channels from eukaryotic cells till now. Although the PVP hinge which is bent the inner-helix of Kv1.2 structure does not exist in KcsA and other prokaryotic potassium channels, the KcsA structure with rigid-body inner-helix was always thought to be the closed template for Kv1.2 and other eukaryotic potassium channels. Here targeted molecular dynamics simulation is performed, in which Kv1.2 is forced to close following from the closed conformation of KcsA. We found that Kv1.2 potassium channel could not match the closed conformation of KcsA because the inner-helix would restore bending at the PVP hinge as the applying force cancelled, while the pore at the cavity-gate region shaped like a sandglass. The conformational transition between the opening and above sandglass like closing could be more effective, which should be the reason why potassium channel evolved to the PXP hinge in eukaryotic cells. |
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