A green deep eutectic solvent-based aqueous two-phase system for protein extracting

Area of Science:

• Biochemistry
• Green Chemistry
• Separation Science

Background:

• Deep eutectic solvents (DES) are emerging as environmentally friendly alternatives to traditional solvents.
• Aqueous two-phase systems (ATPS) are widely used for protein separation and purification.
• Combining DES with ATPS presents a novel strategy for efficient protein extraction.

Purpose of the Study:

• To investigate the application of choline chloride (ChCl)-based DES in ATPS for protein extraction.
• To optimize extraction conditions for bovine serum albumin (BSA) and trypsin (Try).
• To evaluate the structural integrity of extracted proteins and elucidate the extraction mechanism.

Main Methods:

• Synthesis and selection of four ChCl-based DESs.
• Optimization of extraction parameters including DES amount, salt concentration, protein mass, shaking time, temperature, and pH.
• Extraction efficiency determination using optimized conditions.
• Protein structure analysis via UV-Vis, FT-IR, and CD spectroscopy.
• Mechanism exploration using conductivity, dynamic light scattering (DLS), and transmission electron microscopy (TEM).

Main Results:

• ChCl-glycerol was identified as the optimal DES for protein extraction.
• Optimized conditions achieved 98.16% BSA extraction and 94.36% Try extraction efficiency.
• Extraction process demonstrated high precision (RSD < 1.61%) and stability.
• Spectroscopic analysis confirmed no conformational changes in BSA during extraction.
• DES-protein aggregate formation was identified as the key mechanism for separation.

Conclusions:

• ChCl-based DES-ATPS provide an efficient and green method for protein extraction.
• The method preserves the native conformation of proteins.
• This approach holds significant potential for industrial-scale protein separation and purification.