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K+/Na+ selectivity of the KcsA potassium channel from microscopic free energy perturbation calculationsстатья
Дата последнего поиска статьи во внешних источниках: 15 мая 2024 г.
- Авторы: Luzhkov Victor B., Åqvist Johan
- Журнал: Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular Enzymology
- Том: 1548
- Номер: 2
- Год издания: 2001
- Первая страница: 194
- Последняя страница: 202
- DOI: 10.1016/s0167-4838(01)00213-8
- Аннотация: Microscopic molecular dynamics free energy erturbation calculations of the K+/Na+ selectivity in the KcsA potassium channel, based on its experimental three-dimensional structure, are reported. The relative binding free energies for K+ and Na+ in the most relevant ion occupancy states of the four-site selectivity filter are calculated. The previously proposed mechanism for ion permeation through the KcsA channel is predicted, in agreement with available experimental data, to have a significant selectivity for K+ over Na+. The calculations also show that the individual `binding site' selectivities are generally not additive and the doubly loaded states of the filter thus display cooperative effects. The only site that is not K+ selective is that which is located at the entrance to the internal water cavity, suggesting the possibility that internal Na+ could block outward currents.
- Добавил в систему: Лужков Виктор Борисович