title: Characterization of immunoglobulin adsorption on dextran-grafted hydrophobic charge-induction resins: Cross-effects of ligand density and pH/salt concentration.
abstract: Hydrophobic charge-induction chromatography (HCIC) is a promising technology for antibody purification. New HCIC resins MMI-B-XL with dextran-grafted agarose gel as the matrix and 2-mercapto-1-methyl-imidazole (MMI) as the functional ligand were prepared with different ligand densities. The adsorption behaviors (static adsorption equilibrium and adsorption kinetics) of human immunoglobulin G (hIgG) on series of MMI-B-XL resins at varying pHs and salt concentrations were investigated. The cross-effects of solid phase property (ligand density) and liquid phase conditions (pH and salt concentration) were focused. The results showed that the new resins had typical pH-dependent and salt-tolerant characteristics for hIgG adsorption, but differences were found for the resins with different ligand densities. For MMI-B-XL resins with higher ligand density, an obvious higher saturated adsorption capacity (Qm) and effective pore diffusivity (De) could be obtained, which were less affected at pH 7.0∼8.9 but dropped drastically at pH 5.0. Salt addition had less influence on protein adsorption onto MMI-B-XL with higher ligand density. Qm and De both reached minimum values at 0.2mol/L NaCl for all MMI-B-XL resins tested. The results of dynamic binding in the column demonstrated that MMI-B-XL with higher ligand density had better performance for hIgG adsorption, especially under high linear velocities. The mechanism of the cross-effects of ligand density and pH/salt concentration on IgG adsorption was discussed, which provides new insights into protein adsorption and mass transport for dextran-grafted HCIC resins.
authors.affiliation: Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China. Electronic address: lindq@zju.edu.cn.
authors.forename: Dong-Qiang
authors.initials: DQ
authors.lastname: Lin
authors.affiliation: Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Qi-Lei
authors.initials: QL
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China. Electronic address: yaosj@zju.edu.cn.
authors.forename: Shan-Jing
authors.initials: SJ
authors.lastname: Yao
mesh_terms: D000327:Adsorption; D002853:Chromatography, Liquid; D003911:Dextrans / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007093:Imidazoles / Q000737:chemistry*; D007074:Immunoglobulin G / Q000737:chemistry*; D008024:Ligands; D012685:Sepharose / Q000737:chemistry*; D012965:Sodium Chloride
chemical_list: C107674:2-mercapto-1-methylimidazole; D003911:Dextrans; D007093:Imidazoles; D007074:Immunoglobulin G; D008024:Ligands; D012965:Sodium Chloride; D012685:Sepharose
keywords: Dextran-grafted resin; Hydrophobic charge-induction chromatography; Ligand density; Protein adsorption; Salt concentration; pH