Effects of ligand density and pore size on the adsorption of bovine IgG with DEAE ion‐exchange resins

Abstract

Immunoglobulin G is an important plasma protein with many applications in therapeutics and diagnostics, which can be purified effectively by ion exchange chromatography. The ligand densities and pore properties of ion-exchange resins have significant effects on the separation behaviors of protein, however, the understandings are quite limited. In this work, with bovine immunoglobulin as the model IgG, the adsorption isotherms and adsorption kinetics were investigated systematically with series of diethylaminoethyl ion-exchange resins with different ligand densities and pore sizes. The Langmuir equation and pore diffusion model were used to fit the experimental data. The influences of ligand density and pore size on the saturated adsorption capacity, the dissociation constant and the effective diffusivity were discussed. The adsorption capacities increased with the increase of ligand density and the decrease of pore size, and an integrative parameter was proposed to describe the combined effects of ligand density and pore size. It was also found that the effective pore diffusion coefficient of the adsorption kinetics was influenced by pore sizes of resins, but was relatively independent on the ligand densities of resins. For a given protein, the ligand density and pore size should be optimized for improving the protein adsorption.

Economic benefits of membrane chromatography versus packed bed column purification of therapeutic proteins expressed in microbial and mammalian hosts

“…), column parameters (length, diameter, etc.) and operating variables (flow rate, gradient slope, sample loading, etc) …”

Poly(glycidyl methacrylate)‐grafted hydrophobic charge‐induction agarose resins with 5‐aminobenzimidazole as a functional ligand

“…Adsorption kinetics of hIgG on G‐ABI resins with different ligand densities were measured by a batch method, as previously published . Two grams drained HCIC resins were added into 40 mL protein solution (1 mg/mL hIgG in 20 mM sodium phosphate buffer, pH 7.0) in a 50 mL flask.…”

“…The concentration of protein in the suspension was monitored on line by an UV monitor (UV Detector K‐2600, Knauer, Germany). The adsorption kinetics curves were fitted by the pore diffusion model using Matlab 7.5.0 (Mathworks, USA) as had been done in previous studies .The effective pore diffusivity ( D e ) was obtained for G‐ABI resins with different ligand densities.…”

Use of polymeric membranes for purification of an E. coli expressed biotherapeutic protein

“…In another publication, the adsorption capacities of the resin were found to increase with an increase in ligand density and a decrease in pore size, and an integrative parameter was proposed to describe the combined effects of ligand density and pore size. [19] It was also found that the effective pore diffusion coefficient of the adsorption kinetics was influenced by pore sizes of resins, but was relatively independent on the ligand densities of the resins.…”