title: Enhanced extraction of proteins using cholinium-based ionic liquids as phase-forming components of aqueous biphasic systems.
abstract: Aqueous biphasic systems (ABS) composed of ionic liquids (ILs) are promising platforms for the extraction and purification of proteins. In this work, a series of alternative and biocompatible ABS composed of cholinium-based ILs and polypropylene glycol were investigated. The respective ternary phase diagrams, tie-lines, tie-line lengths and critical points were determined at 25°C. The extraction performance of these systems for commercial bovine serum albumin (BSA) was then evaluated. The stability of BSA at the IL-rich phase was ascertained by size exclusion high-performance liquid chromatography and Fourier transform infrared spectroscopy. Appropriate ILs lead to the complete extraction of BSA for the IL-rich phase, in a single step, while maintaining the protein's native conformation. Furthermore, to evaluate the performance of these systems when applied to real matrices, the extraction of BSA from bovine serum was additionally carried out, revealing that the complete extraction of BSA was maintained and achieved in a single step. The remarkable extraction efficiencies obtained are far superior to those observed with typical polymer-based ABS. Therefore, the proposed ABS may be envisaged as a more effective and biocompatible approach for the separation and purification of other value-added proteins.
authors: CICECO-Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors: Maria V
authors: MV
authors: Quental
authors: Environmental Analysis Department, Faculty of Chemistry, University of Gdansk ul. Wita Stwosza , Gdansk, Poland.
authors: Magda
authors: M
authors: Caban
authors: CICECO-Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors: Matheus M
authors: MM
authors: Pereira
authors: Environmental Analysis Department, Faculty of Chemistry, University of Gdansk ul. Wita Stwosza , Gdansk, Poland.
authors: Piotr
authors: P
authors: Stepnowski
authors: CICECO-Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro, Portugal.
authors: João A P
authors: JA
authors: Coutinho
authors: CICECO-Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, Aveiro, Portugal. maragfreire@ua.pt.
authors: Mara G
authors: MG
authors: Freire
mesh_terms: D000818:Animals; D002417:Cattle; D005591:Chemical Fractionation / Q000379:methods*; D002794:Choline / Q000737:chemistry*; D002850:Chromatography, Gel; D052578:Ionic Liquids / Q000737:chemistry*; D055550:Protein Stability; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D012710:Serum Albumin, Bovine
chemical_list: D052578:Ionic Liquids; D011506:Proteins; D012710:Serum Albumin, Bovine; D002794:Choline
keywords: Bovine serum albumin; Cholinium-based aqueous biphasic system; Efficient extraction; Ionic liquid; Purification