Graphene Oxide Composites Enhance Enzyme Activity and Stability

Researchers at the Huazhong University of Science and Technology in Wuhan, People's Republic of China, have developed a new composite material that improves the activity and stability of an enzyme called xylose dehydrogenase (XylB). By incorporating polydopamine (PDA) and polyethyleneimine (PEI) onto graphene oxide, the team created a positively charged surface that enables efficient interactions between the enzyme and the modified composites. Characterization of the composites was performed using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM). Molecular dynamics simulations revealed significant enhancements in thermal stability and catalytic performance of the immobilized enzyme.

Key Takeaways:

• The researchers developed a novel composite material by sequentially grafting PEI onto PDA-anchored graphene oxide for enhanced XylB catalysis.
• The positively charged surface of the composite was designed to explore the potential interactions between the enzyme and the modified composites.
• Characterization using FT-IR, XPS, and SEM confirmed the successful incorporation of the modifier layers on the graphene oxide surface.
• Molecular dynamics simulations identified significant enhancements in thermal stability and catalytic performance of the immobilized enzyme compared to its free counterpart.
• The immobilized enzyme retained over 85% of its activity after four consecutive usage cycles and exhibited double the residual activity compared to free XylB after 30 days of storage at 4°C.
• The immobilized system achieved a 1.4-fold increase in xylonic acid yield relative to the free system.
• This research highlights the potential of advanced material composites in industrial enzyme applications and sets a foundation for further research into sustainable biocatalyst technologies.

Statistics:

• The immobilized enzyme retained over 85% of its activity after four consecutive usage cycles.
• The immobilized enzyme exhibited double the residual activity compared to free XylB after 30 days of storage at 4°C.
• The immobilized system achieved a 1.4-fold increase in xylonic acid yield relative to the free system.

Sources:

• Composites Part B-engineering, 2025;306.
• Elsevier Sci Ltd, 125 London Wall, London, England.
• Huazhong University of Science and Technology, Institute of Resource Biology and Biotechnology, College of Life Sciences and Technology, Dept. of Biotechnologies, Wuhan 430074, People's Republic of China.