Hydrophobically modified quaternized celluloses as new dynamic coatings in CE for basic protein separation.

Area of Science:

• Analytical Chemistry
• Materials Science
• Biochemistry

Background:

• Capillary electrophoresis (CE) requires stable and efficient coatings to improve separation performance.
• Protein adsorption and suboptimal electroosmotic flow (EOF) are common challenges in CE.
• Quaternized cellulose derivatives offer potential as CE coatings but can be further optimized.

Purpose of the Study:

• To synthesize and characterize novel hydrophobically modified quaternized celluloses (HMQCs) as dynamic coatings for CE.
• To evaluate the performance of HMQC coatings in enhancing reversed EOF and suppressing protein adsorption.
• To investigate the impact of HMQC coating parameters on the separation of basic proteins across a range of pH values.

Main Methods:

• Homogeneous synthesis of HMQCs incorporating quaternary ammonium and hexadecyl groups.
• Application of HMQC as dynamic coatings in CE.
• Systematic investigation of polymer concentration, degree of hydrophobic substitution, and buffer pH effects on EOF mobility and protein separation.
• Analysis of basic proteins including lysozyme, ribonuclease A, cytochrome c, bovine pancreatic trypsin inhibitor, and chymotrypsinogen.
• Demonstration of HMQC performance using real-world samples (lysozyme in tear and urine).

Main Results:

• HMQC coatings generated a stronger reversed EOF (approximately 10% increase) compared to standard quaternized cellulose coatings.
• HMQC coatings exhibited superior efficiency in suppressing protein adsorption.
• The HMQC coating significantly improved the separation performance of basic proteins over a broad pH range.
• Complete separation of five model basic proteins was achieved at pH 8.0.
• Successful application of HMQC coatings was demonstrated for the analysis of lysozyme in biological samples.

Conclusions:

• Hydrophobically modified quaternized celluloses (HMQCs) are effective dynamic coatings for capillary electrophoresis.
• HMQC coatings enhance CE performance by increasing reversed EOF and reducing protein adsorption.
• These novel coatings provide robust and versatile separation of basic proteins, with potential applications in clinical diagnostics.