On the Theory of Ion Transport Across the Nerve Membrane, VI. Free Energy and Activation Free Energies of Conformational Change

Publisher Website
Google Scholar
Abstract
Empirical functions, such as n(infinity)(V) and tau(n)(V) (of the Hodgkin-Huxley type), can be recast in terms of more fundamental functions F(V) (related to a conformational free energy change) and theta(V) (related to the corresponding free energies of activation). Examples of F(V) and theta(V) are given, for squid and frog node. F(V) is essentially a quadratic function of V. The possible molecular origin, for protein-like subunits, of the linear (e.g., net charge) and quadratic (e.g., polarizability) terms in F(V) is discussed. The F(V), theta(V) kind of analysis leads rather automatically to a simple explanation of the well-known approximate coincidence in location (V value) of the maximum in tau(n)(V) (time constant) and the steeply rising part of n(infinity)(V) (also m, 1 - h).