Prediction of the elution profiles of proteins in mixed salt systems in hydrophobic interaction chromatography

Abstract

Hydrophobic interaction chromatography (HIC) is often used for purifying proteins. A mathematical model to describe the complex effects of salts on the adsorption equilibria in HIC has recently been introduced by our group. It describes not only the influence of single salts, but also salt mixtures, in which cooperative effects may occur. The influence of the salts is thereby modeled with a Taylor series expansion in the individual ion molarities. In the present study, the model of the adsorption equilibrium is coupled with a lumped kinetic model of the adsorption kinetics to obtain a model of the elution of proteins in HIC adsorption columns. The column model is tested using experimental data on the adsorption of bovine serum albumin (BSA) and lysozyme (LYS) on the mildly hydrophobic resin Toyopearl PPG-600M at pH 7. The studied salts are ammonium chloride, sodium chloride, ammonium sulfate, and sodium sulfate as well as binary and ternary mixtures of them. The parameters of the lumped kinetic model are proteinspecific and were fitted to the elution profiles of the single proteins in presence of single salts. The model was then used to predict the elution profiles of BSA and

Influence of Salts on the Adsorption of Lysozyme on a Mixed-Mode Resin

“…The model is based on a Taylor series expansion in single ion molarities and enables the prediction of equilibrium adsorption isotherms for any mixture of the considered salts up to high ionic strengths. Moreover, this adsorption model was applied for predicting elution profiles of proteins for conceptual process design in HIC [38].…”

Influence of pH value and salts on the adsorption of lysozyme in mixed‐mode chromatography

“…In a recent study, we have developed a mathematical model for describing the influence of the ionic strength of four important salts (sodium chloride, sodium sulfate, ammonium chloride, and ammonium sulfate) on the lysozyme loading of a mixed-mode resin at a constant pH value of 7.0 [36]. This model covers the entire range of technically relevant ionic strengths of the studied salts and follows the approach introduced in earlier work of our group for describing adsorption equilibria in HIC [37,38,39,40], which has already been successfully applied for predicting elution profiles of proteins for the conceptual process design of HIC processes [41]. However, our current model [36] is not capable of describing the influence of the pH value; this gap is filled in the present work.…”

Aggregate Removal by Responsive Electrospun Membrane based Hydrophobic Interaction Chromatography

“…Further membrane modules scale linearly unlike packed beds which are often difficult to scale up [22][23][24]. Numerous previous studies describe the use of membrane based HIC for protein purification [25][26][27][28][29][30][31]. Generally, membrane based HIC is used industrially in flow through mode where the contaminants are bound by the ligands on the membrane surface while the product is recovered in the flowthrough.…”