Insights into the interaction between chitosan and pepsin by optical interferometry.

Area of Science:

• Biomaterials Science
• Biochemistry
• Green Chemistry

Background:

• Polysaccharides and proteins are versatile biocomposites with growing applications in biomedicine and green chemistry.
• Understanding their interactions is crucial for developing novel biomaterials.

Purpose of the Study:

• To investigate the real-time interaction between chitosan and pepsin.
• To elucidate the influence of concentration and pH on this interaction mechanism.

Main Methods:

• Utilized silica colloidal crystal (SCC) films and ordered porous layer interferometry (OPLI) for real-time monitoring.
• Employed zeta potential, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and FTIR microscopy to analyze interaction mechanisms.

Main Results:

• Optical thickness (OT) variations, derived from Fabry-Perot fringes, quantified interaction degree and process.
• Electrostatic attraction between protonated chitosan and pepsin varied with pH.
• Hydrolysis rate and extent correlated positively with pepsin concentration.

Conclusions:

• Chitosan-pepsin interactions are governed by electrostatic forces and enzyme concentration.
• This research provides a foundation for designing advanced polysaccharide-protein biocomposites.