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Detailed Examination of a Single Conduction Event in a Potassium Channel

[Image: see text] Although extensively studied, it has proved difficult to describe in detail how potassium ion channels conduct cations and water. We present a computational study that, by using stratified umbrella sampling, examines nearly an entire conduction event of the Kv1.2/2.1 paddle chimera...

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Detalles Bibliográficos
Autores principales: Fowler, Philip W., Beckstein, Oliver, Abad, Enrique, Sansom, Mark S. P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2013
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797101/
https://www.ncbi.nlm.nih.gov/pubmed/24143269
http://dx.doi.org/10.1021/jz4014079
Descripción
Sumario:[Image: see text] Although extensively studied, it has proved difficult to describe in detail how potassium ion channels conduct cations and water. We present a computational study that, by using stratified umbrella sampling, examines nearly an entire conduction event of the Kv1.2/2.1 paddle chimera and thereby identifies the expected stable configurations of ions and waters in the selectivity filter of the channel. We describe in detail the motions of the ions and waters during a conduction event, focusing on how waters and ions enter the filter, the rotation of water molecules inside the filter, and how potassium ions are coordinated as they move from a water to a protein environment. Finally, we analyze the small conformational changes undergone by the protein, showing that the stable configurations are most similar to the experimental crystal structure.