Bio-inspired nanozyme: a hydratase mimic in a zeolitic imidazolate framework

Area of Science:

• Materials Science
• Biochemistry
• Nanotechnology

Background:

• Nanozymes offer advantages over natural and artificial enzymes but are limited to specific reactions.
• The catalytic mechanisms of many nanozymes remain unclear.
• Zeolitic imidazolate frameworks (ZIFs) are promising candidates for nanozyme development.

Purpose of the Study:

• To develop a new nanozyme based on a bionic zeolitic imidazolate framework.
• To investigate the catalytic activity and mechanism of ZIF-8 nanozyme.
• To explore the potential of ZIFs as a new generation of nanozymes.

Main Methods:

• Synthesis of zeolitic imidazolate framework-8 (ZIF-8) nanozyme.
• Characterization of ZIF-8 structure and active sites.
• Enzyme kinetics studies using p-nitrophenyl acetate, CO2 hydration, and acetylthiocholine hydrolysis assays.
• Comparison of ZIF-8 catalytic performance with human carbonic anhydrase II (hCAII).

Main Results:

• ZIF-8 exhibits a geometric structure similar to hCAII's active center.
• Lewis acid sites on ZIF-8 lower the pKa of water, facilitating nucleophile generation.
• ZIF-8 demonstrated esterase-like activity, promoting p-nitrophenyl acetate hydrolysis.
• ZIF-8 catalyzed CO2 hydration and acetylthiocholine hydrolysis, mimicking hCAII.
• Several ZIFs displayed intrinsic enzyme-like activities.

Conclusions:

• Bionic ZIF-8 nanozymes can effectively mimic natural enzyme active sites.
• The rational design of bionic nanoparticles can lead to advanced nanozymes.
• This study provides a new strategy for developing next-generation nanozymes.