Selectivity of Complex Coacervation in Multi-Protein Mixtures.

Area of Science:

• Biochemistry
• Biophysics
• Cell Biology

Background:

• Liquid-liquid phase separation (LLPS) of biomolecules, especially proteins, is crucial for cellular functions.
• Complex coacervation, a type of LLPS, is a promising method for scalable, aqueous protein purification.
• Current research often overlooks the complexity of biological mixtures, focusing on binary systems.

Approach:

• Engineered proteins were designed for quantitative analysis of complex coacervation in multi-component mixtures.
• A defined protein mixture mimicking the E. coli proteome's charge profile was used.
• Spectrally separated fluorescent proteins enabled direct quantification of individual proteins in each phase.

Key Points:

• Individual protein coacervation behavior in mixtures differed from single-protein systems.
• Subtle biophysical differences influencing protein complex coacervation became apparent in multi-component systems.
• The study elucidated key parameters governing protein complex coacervation.

Conclusions:

• Understanding multi-component phase behavior is essential for advancing complex coacervation applications.
• This work provides a framework for designing targeted protein enrichment strategies.
• The findings contribute to the development of novel protein purification techniques.