Analysis of Ligand-Macromolecule Interactions by Quantitative Affinity Chromatography

Abstract

The establishment of affinity chromatography as a technique for measuring quantitative parameters of macromolecule-ligand interactions (1–3) has been a recent outgrowth of the initial widespread use of this method for purification (4). This analytical potential generally has been based on the competitive elution of a macromolecule from a ligand-affinity matrix with analogous soluble ligand under conditions wherein the macromolecule-insoluble ligand interaction is biospecific. In our own laboratory (1,5,6), we have observed that competitive elution of small zones of enzymes by soluble inhibitor or substrate allows the measurement of equilibrium constants for the binding of the enzymes with both soluble and matrixbound competitive inhibitors. In this paper the overall features and findings of our experiments are reviewed, along with an assessment of some prospective applications of quantitative affinity chromatography for both analysis and purification.