A study of the small-molecule system used to investigate the effect of arginine on antibody elution in hydrophobic charge-induction chromatography.
Hydrophobic charge-induction chromatography (HCIC) using 4-mercaptoethylpyridine (4-MEP) as the ligand is used to purify antibodies. The 4-MEP resin ligand has high affinity for antibodies, which makes it difficult to optimize the elution conditions. Recent studies showed that arginine is effective at eluting and purifying antibodies using the HCIC with 4-MEP. In the present study, we investigated the mechanism of the action of arginine on the interaction between butyl gallate (BG) and the 4-MEP resin as a model system for protein-4-MEP interactions. Equilibrium adsorption experiments showed that arginine has a significant effect on the desorption of BG from the 4-MEP resin and, in fact, is found to exhibit a greater effectiveness than guanidine and urea, which are known denaturants. The calculated binding free energy between a BG molecule and a 4-MEP resin ligand molecule using molecular dynamics simulations was qualitatively consistent with the experimental results. A principal component analysis of the simulations showed that arginine molecules intervene in the interaction between the BG and 4-MEP molecules at a distance of 8.5 Å by entering the space between the phenol and pyridine planes. The present results suggest that arginine has a unique mechanism of interaction with the phenol-pyridine system, which should be associated with the effects of arginine on the protein-4-MEP systems.
Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan.
Atsushi
A
Hirano
Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
Takuya
T
Maruyama
Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
Kentaro
K
Shiraki
Alliance Protein Laboratories, San Diego, CA 92121, USA.
Tsutomu
T
Arakawa
Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Koto, Tokyo 135-0064, Japan. Electronic address: kameda-tomoshi@aist.go.jp.
Tomoshi
T
Kameda
D000906:Antibodies / Q000737:chemistry / Q000302:isolation & purification*; D001120:Arginine / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods; D005707:Gallic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D011725:Pyridines / Q000737:chemistry*
C470522:4-mercaptoethylpyridine; D000906:Antibodies; D011725:Pyridines; D005707:Gallic Acid; C015048:n-butyl gallate; D001120:Arginine
Antibody; Arginine; Binding free energy; Molecular dynamics simulation; Multimodal chromatography