Na⁺/K⁺-ATPase (NKA) is a membrane protein that transports Na⁺ ions out of the cell and brings K⁺ ions into the cell against their concentration gradient. To function, NKA harnesses the chemical energy stored in an ATP molecule to cycle between two major conformational states during active pumping: a high affinity state for Na⁺, and a high affinity state for K⁺. The recent availability of the crystal structures [1] for these states, now makes it possible to computationally determine the factors that control selectivity for Na⁺ versus K⁺ ions.  High selectivity of NKA for Na⁺ or K⁺ may be a result of thermodynamic (different affinities for binding sites) as well as kinetic (barriers along binding pathways) factors.

• Journal article: Molecular simulations and free-energy calculations suggest conformation-dependent anion binding to a cytoplasmic site as a mechanism for Na+/K+-ATPase ion selectivity, Asghar M Razavi, Lucie Delemotte, Joshua R Berlin, Vincenzo Carnevale, and Vincent A Voelz, Journal of Biological Chemistry 292: 12412-12423, 2017 [PDF]
• Conference talk: Razavi, A. M., Carnevale, V., Delemotte, L., & Voelz, V.A. (2015, February 9). Understanding selectivity of the Na+/K+ -ATPase using a computational approach. Platform presentation conducted at the meeting of the Biophysical Society, Baltimore, MD. http://cld.bz/kbr001i#68/z
• Poster: Razavi, A. M., Delemotte, L., Carnevale, V., & Voelz, V.A. (2015, June). Understanding selectivity of Na+/K+-ATPase by computational approach. Poster presented at the Gordon Research Conference, Lewiston, ME. [PDF]
• Poster: Razavi, A. M., Delemotte, L., Carnevale, V., &  Voelz, V.A. (2015, May). Understanding selectivity of Na+/K+ -ATPase by computational approach. Poster presented at the Protein Folding Consortium Workshop, Berkeley, CA. [PDF]

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