K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study.
Molecular dynamics simulations of a bacterial potassium channel (KcsA) embedded in a phospholipid bilayer reveal significant differences in interactions of the selectivity filter with K(+) compared with Na(+) ions. K(+) ions and water molecules within the filter undergo concerted single-file motion...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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2002
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| _version_ | 1826263764344766464 |
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| author | Shrivastava, I Tieleman, D Biggin, P Sansom, MS |
| author_facet | Shrivastava, I Tieleman, D Biggin, P Sansom, MS |
| author_sort | Shrivastava, I |
| collection | OXFORD |
| description | Molecular dynamics simulations of a bacterial potassium channel (KcsA) embedded in a phospholipid bilayer reveal significant differences in interactions of the selectivity filter with K(+) compared with Na(+) ions. K(+) ions and water molecules within the filter undergo concerted single-file motion in which they translocate between adjacent sites within the filter on a nanosecond timescale. In contrast, Na(+) ions remain bound to sites within the filter and do not exhibit translocation on a nanosecond timescale. Furthermore, entry of a K(+) ion into the filter from the extracellular mouth is observed, whereas this does not occur for a Na(+) ion. Whereas K(+) ions prefer to sit within a cage of eight oxygen atoms of the filter, Na(+) ions prefer to interact with a ring of four oxygen atoms plus two water molecules. These differences in interactions in the selectivity filter may contribute to the selectivity of KcsA for K(+) ions (in addition to the differences in dehydration energy between K(+) and Na(+)) and the block of KcsA by internal Na(+) ions. In our simulations the selectivity filter exhibits significant flexibility in response to changes in ion/protein interactions, with a somewhat greater distortion induced by Na(+) than by K(+) ions. |
| first_indexed | 2024-03-06T19:57:01Z |
| format | Journal article |
| id | oxford-uuid:25f69d20-d268-42f8-a12f-8b45c0722a19 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:57:01Z |
| publishDate | 2002 |
| record_format | dspace |
| spelling | oxford-uuid:25f69d20-d268-42f8-a12f-8b45c0722a192022-03-26T11:58:26ZK(+) versus Na(+) ions in a K channel selectivity filter: a simulation study.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:25f69d20-d268-42f8-a12f-8b45c0722a19EnglishSymplectic Elements at Oxford2002Shrivastava, ITieleman, DBiggin, PSansom, MSMolecular dynamics simulations of a bacterial potassium channel (KcsA) embedded in a phospholipid bilayer reveal significant differences in interactions of the selectivity filter with K(+) compared with Na(+) ions. K(+) ions and water molecules within the filter undergo concerted single-file motion in which they translocate between adjacent sites within the filter on a nanosecond timescale. In contrast, Na(+) ions remain bound to sites within the filter and do not exhibit translocation on a nanosecond timescale. Furthermore, entry of a K(+) ion into the filter from the extracellular mouth is observed, whereas this does not occur for a Na(+) ion. Whereas K(+) ions prefer to sit within a cage of eight oxygen atoms of the filter, Na(+) ions prefer to interact with a ring of four oxygen atoms plus two water molecules. These differences in interactions in the selectivity filter may contribute to the selectivity of KcsA for K(+) ions (in addition to the differences in dehydration energy between K(+) and Na(+)) and the block of KcsA by internal Na(+) ions. In our simulations the selectivity filter exhibits significant flexibility in response to changes in ion/protein interactions, with a somewhat greater distortion induced by Na(+) than by K(+) ions. |
| spellingShingle | Shrivastava, I Tieleman, D Biggin, P Sansom, MS K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study. |
| title | K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study. |
| title_full | K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study. |
| title_fullStr | K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study. |
| title_full_unstemmed | K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study. |
| title_short | K(+) versus Na(+) ions in a K channel selectivity filter: a simulation study. |
| title_sort | k versus na ions in a k channel selectivity filter a simulation study |
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