title: Effects of protein conformational changes on separation performance in electrostatic interaction chromatography: unfolded proteins and PEGylated proteins.
abstract: As it is important to understand how protein conformational changes affect the separation performance in ion exchange chromatography (IEC), we investigated two model systems, unfolded proteins (lysozyme and bovine serum albumin) with urea and dithiothreitol, and PEGylated proteins (lysozyme attached with polyethyleneglycol molecular weight 5000). Linear gradient elution IEC experiments were carried out and the data were analysed by our model previously presented in order to obtain the binding site value B and the peak salt concentration I(R). Unfolded proteins (bovine serum albumin and lysozyme) with urea and dithiothreitol showed weaker retention and larger binding site values compared with the values for native proteins. Multiple PEGylated lysozyme peaks were separated, and eluted earlier than the native peak appeared. There is a good correlation between B and I(R) for PEGylated lysozymes.
authors.affiliation: Bioprocess Engineering Laboratory, School of Engineering and Graduate School of Medicine, Yamaguchi University, Ube 755-8611, Japan. shuichi@yamaguchi-u.ac.jp
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Sachie
authors.initials: S
authors.lastname: Fujii
authors.forename: Noriko
authors.initials: N
authors.lastname: Yoshimoto
authors.forename: Parvin
authors.initials: P
authors.lastname: Akbarzadehlaleh
mesh_terms: D001665:Binding Sites; D002852:Chromatography, Ion Exchange / Q000379:methods*; D009113:Muramidase / Q000737:chemistry / Q000302:isolation & purification*; D011092:Polyethylene Glycols / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000032:analysis / Q000737:chemistry*; D012685:Sepharose / Q000737:chemistry
chemical_list: D011506:Proteins; D011092:Polyethylene Glycols; D012685:Sepharose; D009113:Muramidase