Simultaneous Operations of Fractionation and Concentration of Binary Protein Mixtures with Particles of Superabsorbent Hydrogels

Abstract

A new technique has been developed for separating target protein selectively from protein mixtures using superabsorbent crosslinked hydrogels which have a drastic change in volume by absorbing water. In the process, the gel particles swell by absorbing water in an aqueous solution of complex solutions of BSA and myoglobin, and these proteins are simultaneously fractionated by the principle of polyelectrolyte precipitation resulting from electrostatic interactions between the oppositely charged protein and the gel. The experimental data clearly demonstrated that the concentration ratio of BSA markedly increases with the dosage of the gel, while that of myoglobin decreases, resulting in a high degree of fractionation of BSA and myoglobin with the hydrogels. In addition, the variation over time of the concentration ratio of BSA was successfully evaluated by using the equation of motion of the gel network on the basis of the kinetics of swelling of the spherical gel.