title: Stimuli-responsive separation of proteins using immobilized liposome chromatography.
abstract: The possibility of the stimuli-responsive separation of proteins was investigated using immobilized liposome chromatography (ILC) as novel aqueous two-phase systems. The specific capacity factor (k(s)) of beta-galactosidase, obtained by analysis of ILC, was varied by changing the pH of the solution and was maximized at the specific pH of 5 (k(s),max = 5.57). The k(s) values were found to correspond well with their local hydrophobicities, which can be determined by the aqueous two-phase partitioning method. The variation of k(s), therefore, indicates a change in the surface properties of a protein during conformational change under pH stimuli. A similar phenomenon is observed in the case of other proteins (alpha-glucosidase, k(s),max = 11.3 at pH 4; carbonic anhydrase from bovine, k(s),max = 6.53 at pH 4). The difference in the height and/or the position of the peaks of the ks-pH curves of each protein suggests a difference in their pH denaturation in the ILC column. Based on these results, the mutual separation of the above proteins at pH 4 could be successfully performed by selecting their specific capacity factor as a design parameter.
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shimanouchi
authors.forename: S
authors.initials: S
authors.lastname: Morita
authors.forename: H
authors.initials: H
authors.lastname: Umakoshi
authors.forename: R
authors.initials: R
authors.lastname: Kuboi
mesh_terms: D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008081:Liposomes; D011506:Proteins / Q000302:isolation & purification*
chemical_list: D008081:Liposomes; D011506:Proteins