Selectivity and permeation of alkali metal ions in K+-channels.
Ion conduction in K(+)-channels is usually described in terms of concerted movements of K(+) progressing in a single file through a narrow pore. Permeation is driven by an incoming ion knocking on those ions already inside the protein. A fine-tuned balance between high-affinity binding and electrost...
| Egile Nagusiak: | , |
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| Formatua: | Journal article |
| Hizkuntza: | English |
| Argitaratua: |
2011
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| _version_ | 1826307183715811328 |
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| author | Furini, S Domene, C |
| author_facet | Furini, S Domene, C |
| author_sort | Furini, S |
| collection | OXFORD |
| description | Ion conduction in K(+)-channels is usually described in terms of concerted movements of K(+) progressing in a single file through a narrow pore. Permeation is driven by an incoming ion knocking on those ions already inside the protein. A fine-tuned balance between high-affinity binding and electrostatic repulsive forces between permeant ions is needed to achieve efficient conduction. While K(+)-channels are known to be highly selective for K(+) over Na(+), some K(+) channels conduct Na(+) in the absence of K(+). Other ions are known to permeate K(+)-channels with a more moderate preference and unusual conduction features. We describe an extensive computational study on ion conduction in K(+)-channels rendering free energy profiles for the translocation of three different alkali ions and some of their mixtures. The free energy maps for Rb(+) translocation show at atomic level why experimental Rb(+) conductance is slightly lower than that of K(+). In contrast to K(+) or Rb(+), external Na(+) block K(+) currents, and the sites where Na(+) transport is hindered are characterized. Translocation of K(+)/Na(+) mixtures is energetically unfavorable owing to the absence of equally spaced ion-binding sites for Na(+), excluding Na(+) from a channel already loaded with K(+). |
| first_indexed | 2024-03-07T06:59:06Z |
| format | Journal article |
| id | oxford-uuid:ff1fc3aa-939c-4781-ab0f-083aa18cde5d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:59:06Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:ff1fc3aa-939c-4781-ab0f-083aa18cde5d2022-03-27T13:42:14ZSelectivity and permeation of alkali metal ions in K+-channels.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ff1fc3aa-939c-4781-ab0f-083aa18cde5dEnglishSymplectic Elements at Oxford2011Furini, SDomene, CIon conduction in K(+)-channels is usually described in terms of concerted movements of K(+) progressing in a single file through a narrow pore. Permeation is driven by an incoming ion knocking on those ions already inside the protein. A fine-tuned balance between high-affinity binding and electrostatic repulsive forces between permeant ions is needed to achieve efficient conduction. While K(+)-channels are known to be highly selective for K(+) over Na(+), some K(+) channels conduct Na(+) in the absence of K(+). Other ions are known to permeate K(+)-channels with a more moderate preference and unusual conduction features. We describe an extensive computational study on ion conduction in K(+)-channels rendering free energy profiles for the translocation of three different alkali ions and some of their mixtures. The free energy maps for Rb(+) translocation show at atomic level why experimental Rb(+) conductance is slightly lower than that of K(+). In contrast to K(+) or Rb(+), external Na(+) block K(+) currents, and the sites where Na(+) transport is hindered are characterized. Translocation of K(+)/Na(+) mixtures is energetically unfavorable owing to the absence of equally spaced ion-binding sites for Na(+), excluding Na(+) from a channel already loaded with K(+). |
| spellingShingle | Furini, S Domene, C Selectivity and permeation of alkali metal ions in K+-channels. |
| title | Selectivity and permeation of alkali metal ions in K+-channels. |
| title_full | Selectivity and permeation of alkali metal ions in K+-channels. |
| title_fullStr | Selectivity and permeation of alkali metal ions in K+-channels. |
| title_full_unstemmed | Selectivity and permeation of alkali metal ions in K+-channels. |
| title_short | Selectivity and permeation of alkali metal ions in K+-channels. |
| title_sort | selectivity and permeation of alkali metal ions in k channels |
| work_keys_str_mv | AT furinis selectivityandpermeationofalkalimetalionsinkchannels AT domenec selectivityandpermeationofalkalimetalionsinkchannels |