Distinct interactions of Na{sup +} and Ca{sup 2+} ions with the selectivity filter of the bacterial sodium channel Na{sub V}Ab
- Department of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, UZA 2, A-1090 Vienna (Austria)
Highlights: ► Ca{sup 2+} translocates slowly in the filter, due to lack of “loose” knock-on mechanism. ► Identification of a high affinity binding site in Na{sub V}Ab selectivity filter. ► Changes of EEEE locus triggered by electrostatic interactions with Ca{sup 2+} ions. -- Abstract: Rapid and selective ion transport is essential for the generation and regulation of electrical signaling pathways in living organisms. In this study, we use molecular dynamics simulations and free energy calculations to investigate how the bacterial sodium channel Na{sub V}Ab (Arcobacter butzleri) differentiates between Na{sup +} and Ca{sup 2+} ions. Multiple nanosecond molecular dynamics simulations revealed distinct binding patterns for these two cations in the selectivity filter and suggested a high affinity calcium binding site formed by backbone atoms of residues Leu-176 and Thr-175 (S{sub CEN}) in the sodium channel selectivity filter.
- OSTI ID:
- 22224323
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 430, Issue 4; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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