THE BINDING POTENTIAL, A NEGLECTED LINKAGE CONCEPT.

Corresponding to any one of the various thermodynamic potentials P there exists a binding potential Л which is a function of the derivatives, μ , of P with respect to the composition variables for constant values of the physical variables. This binding potential has the property that v i = ∂ JI ∂ μ i where ν 1 , is the ratio of the amount of component i to that of a reference component. By a suitable choice of P and the physical variables the μ 's may be made the same as the ordinary chemical potentials. The introduction of the concept of the binding potential greatly clarifies the definition of linkage groups, linked functions, and linked sites, and suggests the construction of linkage maps. It also leads to a compact expression for the equilibrium constant for a reaction involving macromolecules which combine with several different ligands.