title: Effects of arginine on multimodal anion exchange chromatography.
abstract: The effects of arginine on binding and elution properties of a multimodal anion exchanger, Capto adhere, were examined using bovine serum albumin (BSA) and a monoclonal antibody against interleukin-8 (mAb-IL8). Negatively charged BSA was bound to the positively charged Capto adhere and was readily eluted from the column with a stepwise or gradient elution using 1M NaCl at pH 7.0. For heat-treated BSA, small oligomers and remaining monomers were also eluted using a NaCl gradient, whereas larger oligomers required arginine for effective elution. The positively charged mAb-IL8 was bound to Capto adhere at pH 7.0. Arginine was also more effective for elution of the bound mAb-IL8 than was NaCl. The results imply that arginine interacts with the positively charged Capto adhere. The mechanism underlying the interactions of arginine with Capto adhere was examined by calculating the binding free energy between an arginine molecule and a Capto adhere ligand in water through molecular dynamics simulations. The overall affinity of arginine for Capto adhere is attributed to the hydrophobic and π-π interactions between an arginine side chain and the aromatic moiety of the ligand as well as hydrogen bonding between arginine and the ligand hydroxyl group, which may account for the characteristics of protein elution using arginine.
authors.affiliation: Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8562, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirano
authors.affiliation: Alliance Protein Laboratories, San Diego, CA 92121, United States.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arakawa
authors.affiliation: Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), Koto, Tokyo 135-0064, Japan. Electronic address: kameda-tomoshi@aist.go.jp.
authors.forename: Tomoshi
authors.initials: T
authors.lastname: Kameda
mesh_terms: D000818:Animals; D000838:Anions / Q000737:chemistry*; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D001120:Arginine / Q000737:chemistry*; D002417:Cattle; D002852:Chromatography, Ion Exchange / Q000379:methods*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D016209:Interleukin-8 / Q000276:immunology; D056004:Molecular Dynamics Simulation; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000838:Anions; D000911:Antibodies, Monoclonal; D016209:Interleukin-8; D012710:Serum Albumin, Bovine; D001120:Arginine
keywords: Antibody; Arginine; Free energy; Molecular dynamics simulation; Multimodal chromatography