Adsorption kinetics of β-lactoglobulin on a polyclonal immunochromatographic support

Abstract

β-Lactoglobulin is one of the main components of whey proteins. Among other reasons, its allergenicity makes its determination in hypoallergenic foods and bio-pharmaceutical products necessary. Immunoaffinity chromatography is a widely accepted technique for purification and analysis of proteins. Knowledge of the apparent kinetics of the adsorption of b-lactoglobulin onto the anti-b-lactoglobulin immunochromatographic column is important to optimize the analytical process. High-performance frontal affinity chromatography was used to study the apparent kinetics of the adsorption process. Langmuir and bi-Langmuir kinetic models, assuming one and two kinds of binding sites, respectively, were used to characterize the adsorption kinetics of b-lactoglobulin B on a polyclonal immunoadsorbent. Very good fits were obtained with the bi-Langmuir model for two different concentrations of b-lactoglobulin and this allowed us to calculate the apparent adsorption rate constants and the column capacities for both kinds of sites. Experimental results indicate the possibility that the adsorption process is not irreversible. The values of the apparent dissociation rate constants leading to the best fit were estimated and the affinity constants were calculated. Ó 2002 Elsevier Science B.V. All rights reserved.