Modular assembly of proteins on nanoparticles.

Area of Science:

• Bioconjugation Chemistry
• Nanotechnology
• Protein Engineering

Background:

• Protein properties vary widely, requiring specific nanoparticle bio-conjugation methods for each protein.
• Existing methods often lack universality, limiting their application across diverse protein types.

Purpose of the Study:

• To develop a universal bio-conjugation strategy for gold nanoparticles (GNPs).
• To create a novel recombinant fusion protein for efficient and covalent nanoparticle functionalization.

Main Methods:

• Engineered a fusion protein combining Glutathione S-Transferase (GST) and SpyCatcher domains.
• Characterized GST's ability to bind gold nanoparticles via gold-sulfur bonds (Au-S).
• Demonstrated covalent immobilization of SpyCatcher onto GNPs through GST, preserving functionality.

Main Results:

• The fusion protein GST-SpyCatcher successfully binds to gold nanoparticles (GNPs).
• Immobilized SpyCatcher retains its ability to capture proteins tagged with SpyTag.
• Achieved covalent attachment of SpyTag-modified proteins to GNPs via spontaneous isopeptide bond formation.

Conclusions:

• A universal and efficient bio-conjugation method for gold nanoparticles has been established.
• The GST-SpyCatcher fusion protein system offers a versatile platform for nanoparticle functionalization.
• This approach facilitates covalent protein attachment to GNPs, simplifying bioconjugation processes.