Solvent properties governing protein partitioning in polymer/polymer aqueous two-phase systems

Area of Science:

• Biochemistry
• Physical Chemistry
• Separation Science

Background:

• Aqueous two-phase systems (ATPS) are widely used for protein separation.
• Understanding protein-solvent interactions is crucial for optimizing separation efficiency.

Purpose of the Study:

• To characterize protein-solvent interactions in Dextran-Ficoll, Dextran-PES, and Ficoll-PES systems.
• To correlate protein partitioning behavior with specific molecular properties.

Main Methods:

• Measured protein distribution coefficients in various ATPS.
• Integrated partitioning data with known solvatochromic properties of the systems.
• Analyzed protein susceptibility to solvent dipolarity, hydrogen bonding, and ionic interactions.

Main Results:

• Protein partitioning was adequately described by solute-solvent interaction parameters.
• Relative susceptibilities to solvent dipolarity correlated with hydrogen bond acidity and basicity.
• These interrelationships were consistent across different ATPS and with previous findings for small molecules.

Conclusions:

• Solute-solvent interactions are key determinants of protein partitioning in ATPS.
• The established relationships provide a predictive framework for protein separation.
• This study advances the understanding of molecular interactions in complex aqueous environments.