Ucon-benzoyl dextran aqueous two-phase systems: protein purification with phase component recycling

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Abstract

Benzoyl dextran with a degree of substitution of 0.18 was synthesized by reacting dextran T500 with benzoyl chloride. A new type of aqueous two-phase system composed of benzoyl dextran as bottom phase polymer and the random copolymer of ethylene oxide and propylene oxide (Ucon 50-HB-5100) as top phase polymer has been formed. The phase diagram for the system Ucon 50-HB-5100-benzoyl dextran with a degree of substitution of 0.18 was determined at room temperature. This two-phase system has been used to purify 3-phosphoglycerate kinase from baker's yeast. The top-phase polymer (Ucon) can be separated from target enzyme by increasing the temperature. The bottom-phase polymer (benzoyl dextran) could be recovered by addition of salt. Yeast homogenate was partitioned in a primary Ucon 50-HB-5100-benzoyl dextran aqueous two-phase system. After phase separation the top phase was removed and temperature-induced phase separation was used for formation of a water phase and a Ucon-rich phase. The benzoyl dextran-enriched bottom phase from the primary system was diluted, and the polymer was separated from water by addition of Na2SO4.

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Subject classification (UKÄ) – MANDATORY

  • Biological Sciences

Keywords

  • Aqueous two-phase system, Partitioning, Ucon, Benzoyl dextran, Protein
Original languageEnglish
Pages (from-to)65-70
JournalJournal of Chromatography. B
Volume680
Issue number1-2
Publication statusPublished - 1996
Publication categoryResearch
Peer-reviewedYes