Enzyme Encapsulation in a Porous Hydrogen-Bonded Organic Framework

Area of Science:

• Biotechnology
• Materials Science
• Biochemistry

Background:

• Protection of biological assemblies is crucial for biotechnology applications, including enzyme durability in biocatalysis and biotherapeutics stabilization.
• Current methods face limitations in protecting biomolecules from harsh conditions like elevated temperatures, denaturing agents, and extreme pH levels.

Purpose of the Study:

• To develop and characterize a novel porous hydrogen-bonded organic framework (HOF) for biomolecule stabilization.
• To evaluate the HOF's ability to protect enzymes against various stressors and compare its performance to existing materials like zeolitic imidazolate frameworks (ZIFs).

Main Methods:

• Synthesis of a porous HOF using water-soluble tetra-amidinium and tetracarboxylate building blocks.
• Encapsulation of biomolecules (e.g., catalase, alcohol oxidase) within the HOF structure.
• Assessment of enzyme activity and stability under various conditions (temperature, pH, proteolytic and denaturing agents).

Main Results:

• The HOF successfully encapsulated and stabilized biomolecules, enhancing their resistance to elevated temperatures, proteolytic, and denaturing agents.
• Catalase activity was extended over a broader operable pH range when encapsulated in the HOF.
• Alcohol oxidase, inactive in ZIFs, retained activity when encapsulated within the HOF, highlighting the HOF's unique protective properties.
• The HOF framework readily retains water, contributing to biomolecule protection.

Conclusions:

• The developed HOF provides effective protection and stabilization for biomolecules, crucial for biotechnological applications.
• HOFs present a metal-free, biocompatible alternative to ZIFs, offering larger pore apertures and stability across a wider, biologically relevant pH range.
• This HOF material shows significant potential for improving the durability and applicability of enzymes and biotherapeutics.