ELECTROCHEMICAL MODEL OF VOLTAGE-GATED CHANNELS

An electrochemical model of protein aggregation has been developed based on changes in surface free energy that accompany changes in molecular surface area and charge density. The surface free energy model quantitatively predicts the disaggregatian of hemoglobin tetramers into dimers at alkaline pHs, and also accounts for the energetics of the conformational changes in the reactions of hemoglobin with ligands (e.g., the Bohr effects, the Hill coefficient). Because membrane channels are oligomeric proteins, the model has been applied to channel opening and closing. Many physical properties appear to be direct consequences of this model, including the observed variation of the ion selectivity of voltage-gated channels with gating current and the cooling that accompanies channel opening.