Flow microcalorimetric measurements for bovine serum albumin on reversed-phase and anion-exchange supports under overloaded conditions

Heat of adsorption data using flow microcalorimetry is reported for the adsorption of bovine serum albumin (BSA) on C18 and C4 chromatographic supports. Exothermic heats were obtained in all cases. Data for the effect of salt indicate that conformational changes in adsorbed protein appear to be greatest in the absence of salt. Also, the specific surface area of the support was found to influence behavior more strongly than the length of the carbon ligand. Heats of adsorption of BSA on an ion-exchange support were also measured. Endothermic heats were obtained in all cases. The data indicate that the observed heat effects may be strongly influenced by the release of water from the surface.