Liquid-liquid extraction of lysozyme using a dye-modified ionic liquid.

Area of Science:

• Biochemistry
• Chemical Engineering
• Separation Science

Background:

• Lysozyme is a valuable enzyme with diverse applications.
• Efficient and selective extraction methods are crucial for protein purification.
• Ionic liquids offer unique properties for biomolecule separation.

Purpose of the Study:

• To synthesize a novel affinity-dye ionic liquid, [BMIM]3[CB], for lysozyme extraction.
• To investigate the liquid-liquid extraction of lysozyme using this ionic liquid.
• To evaluate the selectivity and reusability of the extraction system.

Main Methods:

• Synthesis of [BMIM]3[CB] by combining [BMIM][Cl] and the silver salt of Cibacron Blue 3GA (CB).
• Performing liquid-liquid extractions of lysozyme from aqueous and ionic liquid phases.
• Analyzing the effect of pH and ionic strength on lysozyme transfer.
• Assessing the specificity against other proteins like cytochrome c, ovalbumin, and bovine serum albumin.
• Evaluating the reusability of the ionic liquid phase over multiple extraction cycles.

Main Results:

• Optimal lysozyme extraction (>90%) achieved at pH 4 in the aqueous phase.
• Lysozyme transfer to the ionic liquid phase decreased with increasing aqueous phase pH.
• Quantitative recovery of lysozyme from the ionic liquid phase was achieved using 1M KCl solutions (pH 9-11).
• The extraction demonstrated high specificity for lysozyme compared to other tested proteins.
• The ionic liquid phase maintained extraction efficiency after eight cycles.

Conclusions:

• The synthesized [BMIM]3[CB] is an effective affinity-based ionic liquid for selective lysozyme extraction.
• The extraction process is tunable via pH and ionic strength, allowing for efficient capture and release.
• The system exhibits excellent reusability and specificity, making it a promising tool for protein purification.