Kinetic Description of Multiscale Phenomena

The Annual Kinetic FRG Meeting
September 21-25, 2009

CSIC Building (#406), Seminar Room 4122.

Energetic variational approaches for ion channels

Dr. Chun Liu

Penn State University

Abstract:  Ion channels are key components in a wide variety of biological processes, such as nerve impulse, cardiac and muscle contraction, regulating the secretion of hormones into the bloodstream. They are frequent targets in the search of new drugs. Ion channels, like enzymes, have their specific selectivity properties: potassium, sodium, calcium, and chloride channels allow only that type of ions to move through the pores. We will model the selectivities in both calcium and sodium channels by the reduced models, taking into consideration of dielectric coefficients and ion particle sizes, as well as their very different primary structure and properties. The side-chains are represented only as charged spheres (calcium channel EEEA/EEEE; sodium channel DEKA). These self-organized systems will be modeled and analyzed with energetic variational approaches (EnVarA) that were motivated by classical works of Rayleigh and Onsager, and had been employed successfully in various complex fluids recently. Our current numerical simulation of the system, appling to EEEE/DEKA channels, have produced the binding like real calcium/sodium channels. Time dependent simulation gives the currents resemble the classical Hodgkin-Huxley description of voltage activated sodium or potassium channels. In this talk, I will discuss the some of the related biological, physics, chemistry and mathematical issues.