Adsorption, desorption and re-adsorption of proteins on solid surfaces

Four proteins, bovine serum albumin (BSA), calcium-containing and calcium-depleted bovine α-lactalbumin (BαLA( + Ca 2+) and BαLA( − Ca 2+) respectively) and hen's egg lysozyme (LSZ), were adsorbed from an aqueous solution on to finely dispersed particles of silica and hematite. Subsequently, the proteins were displaced from the surfaces by morpholine and the desorbed proteins were exposed again to the surfaces of hematite and silica. For this re-adsorption both the kinetics and the isotherms at prolonged incubation times were determined. The differences in the adsorption between the respective native proteins as well as the influence of pre-adsorption and subsequent displacement on the re-adsorption behavior could be related to the variation in stability of the protein structure.