Voltage-Sensitive Sodium Channels: Molecular Structure and Function

The improvement of techniques for correlating selective chemical modifications of the protein structure with functional behavior should provide an important avenue for dissecting the mechanisms of gating, conductance, selectivity, and sensitivity to neurotoxins and drugs. These methods are likely to be an important complement to site-directed mutagenesis studies. Voltage-sensitive Na channels are conformationally regulated molecules. Classical conformational mechanisms have involved allostery in enzymes and in binding proteins, such as hemoglobin. Allosteric mechanisms have been historically studied in symmetrical oligomeric proteins, in which the binding of a substrate or effector ligand causes a cooperative change in conformation and a resultant shift in catalytic efficiency or binding affinity.