The dielectric properties of water within model transbilayer pores
Ion channels contain extended columns of water molecules within their transbilayer pores. The dynamic properties of such intrapore water have been shown to differ from those of water in its bulk state. In previous molecular dynamics simulations of two classes of model pore (parallel bundles of Ala20...
| Main Authors: | , , , |
|---|---|
| Other Authors: | |
| Format: | Journal article |
| Language: | English |
| Published: |
Elsevier
1997
|
| Subjects: |
| _version_ | 1826304924316598272 |
|---|---|
| author | Sansom, M Smith, G Adcock, C Biggin, P |
| author2 | Biophysical Society |
| author_facet | Biophysical Society Sansom, M Smith, G Adcock, C Biggin, P |
| author_sort | Sansom, M |
| collection | OXFORD |
| description | Ion channels contain extended columns of water molecules within their transbilayer pores. The dynamic properties of such intrapore water have been shown to differ from those of water in its bulk state. In previous molecular dynamics simulations of two classes of model pore (parallel bundles of Ala20 alpha-helices and antiparallel barrels of Ala10 beta-strands), a substantially reduced translational and rotational mobility of waters was observed within the pore relative to bulk water. Molecular dynamics simulations in the presence of a transpore electrostatic field (i.e., a voltage drop along the pore axis) have been used to estimate the resultant polarization (due to reorientation) of the intrapore water, and hence to determine the local dielectric behavior within the pore. It is shown that the local dielectric constant of water within a pore is reduced for models formed by parallel alpha-helix bundles, but not by those formed by beta-barrels. This result is discussed in the context of electrostatics calculations of ion permeation through channels, and the effect of the local dielectric of water within a helix bundle pore is illustrated with a simple Poisson-Boltzmann calculation. |
| first_indexed | 2024-03-07T06:25:05Z |
| format | Journal article |
| id | oxford-uuid:f401eefa-40a6-45ca-8c13-7a1b4eb4b78b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:25:05Z |
| publishDate | 1997 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:f401eefa-40a6-45ca-8c13-7a1b4eb4b78b2022-03-27T12:16:31ZThe dielectric properties of water within model transbilayer poresJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f401eefa-40a6-45ca-8c13-7a1b4eb4b78bMolecular biophysics (biochemistry)EnglishOxford University Research Archive - ValetElsevier1997Sansom, MSmith, GAdcock, CBiggin, PBiophysical SocietyIon channels contain extended columns of water molecules within their transbilayer pores. The dynamic properties of such intrapore water have been shown to differ from those of water in its bulk state. In previous molecular dynamics simulations of two classes of model pore (parallel bundles of Ala20 alpha-helices and antiparallel barrels of Ala10 beta-strands), a substantially reduced translational and rotational mobility of waters was observed within the pore relative to bulk water. Molecular dynamics simulations in the presence of a transpore electrostatic field (i.e., a voltage drop along the pore axis) have been used to estimate the resultant polarization (due to reorientation) of the intrapore water, and hence to determine the local dielectric behavior within the pore. It is shown that the local dielectric constant of water within a pore is reduced for models formed by parallel alpha-helix bundles, but not by those formed by beta-barrels. This result is discussed in the context of electrostatics calculations of ion permeation through channels, and the effect of the local dielectric of water within a helix bundle pore is illustrated with a simple Poisson-Boltzmann calculation. |
| spellingShingle | Molecular biophysics (biochemistry) Sansom, M Smith, G Adcock, C Biggin, P The dielectric properties of water within model transbilayer pores |
| title | The dielectric properties of water within model transbilayer pores |
| title_full | The dielectric properties of water within model transbilayer pores |
| title_fullStr | The dielectric properties of water within model transbilayer pores |
| title_full_unstemmed | The dielectric properties of water within model transbilayer pores |
| title_short | The dielectric properties of water within model transbilayer pores |
| title_sort | dielectric properties of water within model transbilayer pores |
| topic | Molecular biophysics (biochemistry) |
| work_keys_str_mv | AT sansomm thedielectricpropertiesofwaterwithinmodeltransbilayerpores AT smithg thedielectricpropertiesofwaterwithinmodeltransbilayerpores AT adcockc thedielectricpropertiesofwaterwithinmodeltransbilayerpores AT bigginp thedielectricpropertiesofwaterwithinmodeltransbilayerpores AT sansomm dielectricpropertiesofwaterwithinmodeltransbilayerpores AT smithg dielectricpropertiesofwaterwithinmodeltransbilayerpores AT adcockc dielectricpropertiesofwaterwithinmodeltransbilayerpores AT bigginp dielectricpropertiesofwaterwithinmodeltransbilayerpores |