High-performance affinity chromatography and immobilized serum albumin as probes for drug- and hormone-protein binding

The binding of drugs and hormones to proteins within the blood is an important process in determining the transport, excretion, metabolism and activity of such agents. This paper discusses the combined use of immobilized serum albumin and high-performance affinity chromatography (HPAC) as tools for the study of such binding processes. The general approaches that are used in such work and are illustrated by several examples taken from previous work in the author’s laboratory. The type of qualitative and quantitative information that can be obtained by such work is described, including the comparison of relative binding affinities, competitive displacement by other agents or the measurement of equilibrium and rate constants based on immobilized albumin columns. A comparison is also provided between the results that are obtained by these methods and those that are provided by solution-phase albumin. Some newer advances that are highlighted include use of HPAC to examine the binding of non-polar compounds to albumin, the effects of binding site heterogeneity on HPAC measurements and the use of chemically-modified albumin as a tool to examined the site-specific interactions of solutes with albumin.