Power to the protein: enhancing and combining activities using the Spy toolbox

Area of Science:

• Biotechnology
• Molecular Biology
• Protein Engineering

Background:

• Proteins exhibit vast diversity in shape, size, and function, necessitating universal methods for analysis and application.
• The SpyTag/SpyCatcher system provides a genetically encoded protein ligation technology.

Purpose of the Study:

• To review the SpyTag technology and its broad applications in detecting and controlling protein behavior.
• To highlight the versatility and potential of SpyTag/SpyCatcher in various scientific fields.

Main Methods:

• SpyTag and SpyCatcher, genetically encoded protein fragments, form a spontaneous and irreversible isopeptide bond.
• Development of novel variants for rapid, reversible, or surface-anchored protein conjugation.
• Utilizing scaffolds for assembling SpyTag-fusions into defined multimeric structures and networks.

Main Results:

• SpyTag/SpyCatcher enables rapid, irreversible, or reversible protein conjugation with applications in purification and cellular dynamics.
• Successful anchoring of SpyTag-linked proteins to diverse nanoparticles and surfaces.
• Mechanical stability of SpyTag/SpyCatcher facilitates studies of protein folding and force sensitivity.
• Assembly of defined protein multimers (dimers to 180-mers) and networks (1D, 2D, 3D).
• Applications in vaccine development (malaria, HIV, cancer), enhanced enzyme biocatalysis, and modular derivatization of biomolecules.
• In vivo applications include protein trafficking imaging, CAR-T cell retargeting, cardiac function studies, and nucleosome positioning control.

Conclusions:

• SpyTag technology offers a powerful and versatile platform for protein engineering and functional manipulation.
• Its simple genetic encoding and rapid reaction kinetics present significant opportunities for advancing protein-based applications.
• Future directions include addressing limitations and expanding the scope of SpyTag/SpyCatcher applications.