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

Area of Science:

• Biochemistry
• Polymer Chemistry
• Separation Science

Background:

• Aqueous two-phase systems (ATPS) are valuable for bioseparations.
• Developing novel ATPS with tunable properties is crucial for efficient purification.
• Benzoyl dextran and ethylene oxide/propylene oxide copolymers offer potential for new ATPS.

Purpose of the Study:

• To synthesize benzoyl dextran with a specific degree of substitution.
• To form and characterize a new aqueous two-phase system using benzoyl dextran and Ucon 50-HB-5100.
• To evaluate the system's efficacy in purifying 3-phosphoglycerate kinase from baker's yeast.

Main Methods:

• Synthesis of benzoyl dextran (DS 0.18) from dextran T500 and benzoyl chloride.
• Determination of the phase diagram for the Ucon 50-HB-5100/benzoyl dextran system at room temperature.
• Application of the ATPS for partitioning and purifying 3-phosphoglycerate kinase from yeast homogenate, utilizing temperature and salt for polymer separation.

Main Results:

• A novel aqueous two-phase system was successfully formed using benzoyl dextran and Ucon 50-HB-5100.
• The phase diagram of the system was established.
• 3-phosphoglycerate kinase was effectively purified from yeast homogenate using this ATPS, with facile separation of the Ucon and benzoyl dextran polymers.

Conclusions:

• The Ucon 50-HB-5100/benzoyl dextran system is a viable and effective medium for enzyme purification.
• The system allows for efficient separation of target proteins and recovery of the phase-forming polymers.
• This novel ATPS demonstrates potential for biotechnological applications in bioseparations.