Analysis of solution-phase biomolecular interactions by liquid chromatography: General strategies and recent developments.

The analysis of biomolecular interactions is important in characterizing and understanding many fundamental processes that occur in the body and biological systems. A variety of methods are available for studying the extent and rate of binding of these interactions. Some of these techniques are homogeneous methods, with all interacting components being present in the solution-phase, while others are heterogeneous, such as involving both solution-phase and solid-phase components. LC and HPLC have often been used to study biomolecular processes. Although these chromatographic methods make use of both a liquid phase (i.e., the mobile phase and applied samples) and a solid phase (the stationary phase and support), they can be used to study solution-phase interactions. This review examines several strategies that have been developed and employed to use LC and HPLC for this purpose. These strategies include the Hummel-Dreyer method, solution-phase frontal analysis, and the use of physical entrapment for a soluble component of a biomolecular interaction. Other strategies that are discussed are those in which the stationary phase of the column is used as a secondary component or capture agent when studying a solution-phase interaction, as occurs in normal-role affinity chromatography and ultrafast affinity extraction. The general principles for each of these strategies will be considered, along with their advantages, potential limitations, and applications.