Modeling of Protein Adsorption in Membrane Affinity Chromatography

Abstract

For the design of affinity membranes protein adsorption in membrane affinity chromatography (MAC) was studied by frontal analysis. According to fast mass transfer, small thickness of affinity membranes and high affinity between the protein and the ligand, an ideal adsorption (IA) model was proposed for MAC and was used together with equilibrium‐dispersive (E‐D) model to describe the adsorption of bovine serum albumin (BSA) onto cellulose diacetate/polyethyleneimine (CA/PEI) blend membranes with and without Cu²⁺ chelating. E‐D model was found to better describe the initial region of experimental breakthrough curves. The influence of axial dispersion was revealed and it showed the importance of design of the module to homogenously distribute feed solution. IA model was found to be better for the whole experimental breakthrough curve. According to it, the capacity of affinity membranes and the specificity of the interaction are of equal importance for the design of affinity membranes. An optimum feed concentration was also found in the operation of MAC. The discrepancy between experimental optimum feed concentrations and predicted ones from IA model may be due to the ignorance of some experimental effects such as axial dispersion.

Keywords:

• Membrane affinity chromatography
• Ideal adsorption model
• Equilibrium‐dispersive model
• Cellulose diacetate/polyethyleneimine blend membranes
• Frontal analysis
• Bovine serum albumin

Acknowledgments

Financial support of this research by grant of the National Nature Science Foundation of China (20075031) is gratefully acknowledged.