Characterization of Copolymer Dehypon® LS 54 and Its Application for Aqueous Two-Phase Systems Paired with the Waxy Maize Starch for Protein Extraction

Abstract

A thermo-separating aqueous two-phase system composed of Dehypon® LS 54, a polymeric surfactant and the waxy maize starch (amylopectin starch) has been used for partitioning of cutinase as a model protein. Dehypon® LS 54 were characterized by using 1H NMR spectroscopy to get information regarding the chemical structure and to confirm the presence of aliphatic moiety group in this copolymer. The phase diagram obtained for these novel polymer-polymers two-phase system shows two-phases with high polymer concentration. The waxy maize starch is enriched in the bottom phase while the copolymer Dehypon® LS 54 is found in the upper phase. Since this copolymer (Dehypon® LS 54) is thermo-reactive, the upper phase can be removed and heated above the copolymer’s cloud-point which resulting in the formation of a new two-phase system with a lower water phase, containing the target protein and an upper is copolymer-rich phase. Our results show that systems formed by waxy maize starch and Dehypon® LS 54 could become an alternative system to be used in large scale protein and enzyme purification due to their low cost, and also because they offer a viable solution to problems of polymer removal and recycling which makes this system more attractive.