Stepwise Preparation of a Polymer Comprising Protein Building Blocks on a Solid Support for Immunosensing Platform

Area of Science:

• Biotechnology
• Biosensing
• Protein Engineering

Background:

• Antibody immobilization is critical for immunosensor performance.
• Existing methods can be limited in stability and control.

Purpose of the Study:

• To develop a novel, robust antibody immobilization strategy for enhanced immunosensing.
• To create an adjustable protein-polymer chain for controlled antibody binding.

Main Methods:

• Utilized a Z-domain-containing protein-polymer chain for antibody immobilization.
• Employed a unique biotinylation system from Sulfolobus tokodaii involving biotin protein ligase (BPL) and biotin carboxyl carrier protein (BCCP).
• Engineered fusion proteins (BZB) and BPL dimers, applied alternately to build polymer chains on a surface plasmon resonance sensor chip.

Main Results:

• Successfully constructed protein-polymer chains with multiple Z-domain units.
• Demonstrated adjustable antibody-binding capacity by controlling polymer density and chain length.
• Achieved highly stable antibody immobilization via the engineered protein system.

Conclusions:

• The proposed Z-domain protein-polymer immobilization method offers a versatile and effective approach for immunosensor development.
• This technique allows for fine-tuning of antibody density and binding affinity, leading to improved sensor performance.