Insights into protein sorption and desorption on dextran-modified ion-exchange media

Abstract

A diverse array of experimental techniques was used to compare protein sorption and transport on agarose-based resins with and without dextran extenders. Van't Hoff plots indicated similar trends for lysozyme on the resins, with enthalpically dominated sorption. Salt breakthrough curves demonstrated significant exclusion of salt from the dextran, consistent with Donnan equilibrium predictions. Polarization-sensitive confocal microscopy and fluorescence recovery after photobleaching (FRAP) exhibited little effect of dextran modification on the respective rotational and translation mobilities of adsorbed protein at equilibrium. Finally, confocal microscopy imaging of intraparticle elution behavior showed that slower elution can occur for dextran-modified resins. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.