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Research Abstracts Online
January 2010 - March 2011

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University of Minnesota Twin Cities
Medical School
Department of Integrative Biology and Physiology

PI: Jürgen F. Fohlmeister, Associate Fellow

Mechanisms and Distribution of the Spiking Ion Channels in Neurons

Voltage-gating kinetic schemes for sodium- and potassium-channels for nerve (and muscle) are being developed in which every conformational state (of gating) is individually recognized. Almost all species of Na- and K-channels appear to be structurally similar in that their primary, "alpha,” subunits are composed of four or five similar repeat sequences in a single protein molecule, in conjunction with smaller and molecularly distinct "beta" polypeptide subunits. Currently, highly simplified parallel and sequential kinetic schemes treat many of the subunits and transition paths as interchangeable, thus severely restricting detailed analysis. The present research, in contrast, employs higher-dimensional geometries (4-, 5- and higher dimensional cubes) as the basis for the kinetic diagrams. This treats every possible individual kinetic state and path in the channel gating mechanism as unique. The results are expected to yield fundamental advances in ion channel gating (e.g., evaluating the robustness of the basic channel-structural design and subunit strategy), as well as detailed effects of specific channel mutations. Ion channel subtypes NaV1.1, 1.2, 1.3, 1.6, and Kv1.1 through 1.6 specifically will be evaluated. MSI resources are employed for large-scale computation and graphics representation in the higher dimensional kinetic regimes.