Rational design of mini protein mimicking uricase: Encapsulation in ZIF-8 for uric acid detection

Area of Science:

• Biochemistry
• Biotechnology
• Biosensing

Background:

• Uricase enzymes are crucial for uric acid metabolism.
• Developing stable and efficient uric acid biosensors remains a challenge.
• Mini proteins offer a potential alternative to full-length enzymes.

Purpose of the Study:

• To design and characterize mini proteins that mimic uricase activity.
• To develop a stable bioreceptor for uric acid sensing.
• To investigate the electrochemical detection of uric acid using a novel mini protein-based sensor.

Main Methods:

• Design of five mini proteins (20-100 amino acids) based on Arthrobacter globiformis uricase structure.
• Molecular docking to select the smallest mini protein (mp20).
• Recombinant protein purification, characterization (binding, stability), and electrochemical sensor fabrication (mp20@ZIF-8 on rGO/SPCE).
• Electrochemical analysis using cyclic voltammetry and electrochemical impedance spectroscopy (EIS).

Main Results:

• The smallest mini protein, mp20, was selected based on docking analysis.
• Purified mp20 exhibited specific binding to uric acid and high thermotolerance (10-100°C).
• The fabricated electrochemical sensor demonstrated sensitive detection of uric acid via substrate-mp20 interaction, indicated by cyclic voltammetry and EIS.

Conclusions:

• Mini proteins can be designed to mimic enzyme active sites.
• mp20 demonstrates excellent stability and specific uric acid binding, suitable for bioreceptor applications.
• The developed electrochemical sensor shows promise for sensitive and stable uric acid detection.