Analysis of solute-protein interactions and solute-solute competition by zonal elution affinity chromatography

•Zonal elution can be used in affinity chromatography to study solute-protein binding.•Several solute-proteins or solute-receptor systems have been studied by this method.•The strength of binding and location of binding sites can be examined by zonal elution.•Competition studies and the analysis of allosteric effects are possible as well.•Several other applications for zonal elution-based binding studies are also discussed. Many biological processes involve solute-protein interactions and solute-solute competition for protein binding. One method that has been developed to examine these interactions is zonal elution affinity chromatography. This review discusses the theory and principles of zonal elution affinity chromatography, along with its general applications. Examples of applications that are examined include the use of this method to estimate the relative extent of solute-protein binding, to examine solute-solute competition and displacement from proteins, and to measure the strength of these interactions. It is also shown how zonal elution affinity chromatography can be used in solvent and temperature studies and to characterize the binding sites for solutes on proteins. In addition, several alternative applications of zonal elution affinity chromatography are discussed, which include the analysis of binding by a solute with a soluble binding agent and studies of allosteric effects. Other recent applications that are considered are the combined use of immunoextraction and zonal elution for drug-protein binding studies, and binding studies that are based on immobilized receptors or small targets.