Interactions and Transport of Charged Species in Bulk and at Interfaces
Charge Transport at Biological Interfaces: Insights from Molecular Dynamics SimulationsVania Calandrini
Coauthor(s) : Chao Zhang [1,2], Denis G. Knyazev , Yana A. Vereshaga , Jens Dreyer [1,2], Emiliano Ippoliti [1,2], Trung Hai Nguyen , Justin Finnerty , P. Strodel , Bob Eisenberg , Paolo Carloni [1,2], and Peter Pohl 
 German Research School for Simulation Sciences, Forschungszentrum Jülich, Germany  IAS5/INM9 Forschungszentrum Jülich, Germany  Institute of Biophysics, Johannes Kepler University, Linz, Austria  Rush University Medical Center, Chicago, USA
Monovalent ions (Na+, K+, Cl-, H+) are ubiquitously present in biological systems. Among them, Na+, K+ and Cl- are the most abundant; they regulate metabolism and signaling transduction through transmembrane concentration gradients  and stabilize proteins, lipids, and nucleic acids through both specific and non-specific interactions [2,3]. Lateral H+ migration along membranes  is of vital importance for cellular energy homeostasis and various proton-coupled transport processes . For instance, the synthesis of adenosine triphosphate (ATP), the free energy carrier in living systems, would cease if specific membrane-bound enzymes (proton pumps and ATP synthase as the proton source and the proton sink, respectively) would stop creating and consuming a transmembrane proton gradient .
Most of what we know today about the biophysical properties of monovalent ions has been discovered by experiments, but an increasingly important role - complementary to experiment - is played by molecular simulations. Here, I will provide with an overview of the HPC-based contributions from our group on the transport properties of monovalent ions at water-hydrophobic interfaces [6,7], and the energetics of ion permeation through membrane channels [8-10].
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