Anchoring Effect-Induced Conformation Remodeling in Epoxy-Functionalized Covalent Organic Frameworks for Enhanced...

Area of Science:

• Materials Science
• Biochemistry
• Nanotechnology

Background:

• Enzyme immobilization is crucial for enhancing enzyme stability and reusability.
• Covalent organic frameworks (COFs) offer tunable structures for effective biomolecule immobilization.
• Understanding the impact of immobilization methods on enzyme structure and activity is key.

Purpose of the Study:

• To investigate the
• anchoring effect" of covalent immobilization on enzyme performance.
• To immobilize glucose oxidase (GOx) onto an epoxy-functionalized COF (oCOF-TATP).
• To evaluate the structural and catalytic enhancements of covalently immobilized GOx.

Main Methods:

• Covalent immobilization of glucose oxidase (GOx) onto epoxy-functionalized COF (oCOF-TATP).
• Enzyme loading quantification and secondary structure analysis (e.g., circular dichroism).
• Molecular dynamics simulations to probe structural changes and active site accessibility.
• Enzymatic activity assays and reusability tests.

Main Results:

• Covalent immobilization increased GOx loading to 40 mg/g compared to 26 mg/g for physical adsorption.
• Immobilization induced a shift from α-helix to β-sheet structure, enhancing rigidity and active site exposure.
• Turnover rate (kcat) and catalytic efficiency (kcat/KM) increased to 197% and 388% of free GOx, respectively.
• Immobilized GOx showed 115% product yield and retained >95% activity after six cycles.

Conclusions:

• The "anchoring effect" via covalent bonding significantly enhances enzyme catalytic efficiency and operational stability.
• COFs serve as effective platforms for enzyme immobilization, improving performance through structural modulation.
• This study presents a novel strategy for optimizing enzyme performance using tailored nanomaterials.