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  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]
About the author asgharrazavi
Asghar Razavi is a postdoctoral associate at the Department of Physiology and Biophysics at Weill Cornell Medical College of Cornell University. He received his Ph.D. in Computational Chemistry and Biophysics from Temple University, Philadelphia, USA. His current research at the Weinstein lab focuses on developing molecular level quantitative kinetic models to understand thermodynamics, kinetics, and conformational pathways during function of neurotransmitter transporters and G protein-coupled receptors.