MolecularStrategies to Achieve Selective Conductancein NaK Channel Variants.
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| Title: | MolecularStrategies to Achieve Selective Conductancein NaK Channel Variants. |
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| Authors: | Wang, Yibo1, Chamberlin, Adam C.1, Noskov, Sergei Yu.1 |
| Source: | Journal of Physical Chemistry B. Feb2014, Vol. 118 Issue 8, p2041-2049. 9p. |
| Subjects: | Molecular dynamics, Crystallization, Ion channels, Chemical kinetics, Coordination compounds |
| Abstract: | A recentcrystallization of several ion channels hasprovided strongimpetus for efforts aimed at understanding the different strategiesemployed by nature for selective ion transport. In this work, we usedtwo variants of the selectivity filter of NaK channel to explore molecularmechanisms that give rise to K+-selectivity. We computedone-dimensional (1D) and two-dimensional (2D) potentials of mean force(PMFs) for ion permeation across the channel. The results indicatethat the energies for Na+and K+permeationacross the selectivity filter display significant differences in positionsof the binding sites and barriers. One characteristic signature ofa K+-selective channel is the apparent preservation ofthe site analogous to that of S2 in KcsA. The S2-bound ion can bealmost ideally dehydrated and coordinated by 6 to 8 carbonyls. Ina striking contrast, the PMFs controlling transport of ions in a nonselectivevariant show almost identical profiles for either K+orNa+and significant involvement of water molecules in ioncoordination across the entire selectivity filter. An analysis ofdifferences in 1D PMFs for Na+and K+suggeststhat coordination number alone is an insufficient predictor of siteselectivity, while chemical composition (ratio of carbonyls and watermolecules) correlates well with preference for K+. Multi-ioneffects such as dependence of the barriers and wells for permeantion on the type of copermeant ion were found to play a significantrole in the selectivity signature of the channel as well. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Physical Chemistry B is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 94765790 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: MolecularStrategies to Achieve Selective Conductancein NaK Channel Variants. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Wang%2C+Yibo%22">Wang, Yibo</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Chamberlin%2C+Adam+C%2E%22">Chamberlin, Adam C.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Noskov%2C+Sergei+Yu%2E%22">Noskov, Sergei Yu.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Physical+Chemistry+B%22">Journal of Physical Chemistry B</searchLink>. Feb2014, Vol. 118 Issue 8, p2041-2049. 9p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Molecular+dynamics%22">Molecular dynamics</searchLink><br /><searchLink fieldCode="DE" term="%22Crystallization%22">Crystallization</searchLink><br /><searchLink fieldCode="DE" term="%22Ion+channels%22">Ion channels</searchLink><br /><searchLink fieldCode="DE" term="%22Chemical+kinetics%22">Chemical kinetics</searchLink><br /><searchLink fieldCode="DE" term="%22Coordination+compounds%22">Coordination compounds</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: A recentcrystallization of several ion channels hasprovided strongimpetus for efforts aimed at understanding the different strategiesemployed by nature for selective ion transport. In this work, we usedtwo variants of the selectivity filter of NaK channel to explore molecularmechanisms that give rise to K+-selectivity. We computedone-dimensional (1D) and two-dimensional (2D) potentials of mean force(PMFs) for ion permeation across the channel. The results indicatethat the energies for Na+and K+permeationacross the selectivity filter display significant differences in positionsof the binding sites and barriers. One characteristic signature ofa K+-selective channel is the apparent preservation ofthe site analogous to that of S2 in KcsA. The S2-bound ion can bealmost ideally dehydrated and coordinated by 6 to 8 carbonyls. Ina striking contrast, the PMFs controlling transport of ions in a nonselectivevariant show almost identical profiles for either K+orNa+and significant involvement of water molecules in ioncoordination across the entire selectivity filter. An analysis ofdifferences in 1D PMFs for Na+and K+suggeststhat coordination number alone is an insufficient predictor of siteselectivity, while chemical composition (ratio of carbonyls and watermolecules) correlates well with preference for K+. Multi-ioneffects such as dependence of the barriers and wells for permeantion on the type of copermeant ion were found to play a significantrole in the selectivity signature of the channel as well. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Physical Chemistry B is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/jp4107537 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 9 StartPage: 2041 Subjects: – SubjectFull: Molecular dynamics Type: general – SubjectFull: Crystallization Type: general – SubjectFull: Ion channels Type: general – SubjectFull: Chemical kinetics Type: general – SubjectFull: Coordination compounds Type: general Titles: – TitleFull: MolecularStrategies to Achieve Selective Conductancein NaK Channel Variants. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Wang, Yibo – PersonEntity: Name: NameFull: Chamberlin, Adam C. – PersonEntity: Name: NameFull: Noskov, Sergei Yu. IsPartOfRelationships: – BibEntity: Dates: – D: 27 M: 02 Text: Feb2014 Type: published Y: 2014 Identifiers: – Type: issn-print Value: 15206106 Numbering: – Type: volume Value: 118 – Type: issue Value: 8 Titles: – TitleFull: Journal of Physical Chemistry B Type: main |
| ResultId | 1 |
