The effects of concentration and adsorption time on the elutability of adsorbed proteins in surfactant solutions of varying structures and concentrations

Abstract

The elution of proteins adsorbed to solid surfaces in the presence of surfactants has previously been shown to depend on surface chemistry as well as protein surface residence time and therefore serves as a measure of the protein-surface binding strength. In this study, we have examined the effect of adsorption and elution conditions on the elutability of baboon fibrinogen and albumin from polyethylene and polystyrene. The adsorption variables studied were protein concentration and adsorption time. In the elution step, the influence of detergent concentration and chemical structura, and the ionic strength were examined. The minimum or threshold surfactant concentration required to effect elution varied when protein layers were adsorbed from various concentrations for equal times. On the other hand, proteins adsorbed from equal solution concenrations for various times required equal threshold surfactant concentrations to be eluted. The maximum elution level, however, decreased with increases in the protein's surface residence time, and with decreased protein surface concentration. Transition rates to nonelutable states varied substantially between polyethylene and polystyrene. In addition, certain featues of the elution behavior closely reflected features of the surfactant's aqueous phase behavior.