Site-Specific Fluorogenic Protein Labelling Agent for Bioconjugation.

Area of Science:

• Chemical Biology
• Bioconjugation Chemistry
• Protein Engineering

Background:

• Therapeutic agents often utilize small molecules conjugated to biomolecules via linkers.
• Developing efficient and specific conjugation methods is crucial for creating novel protein-cargo conjugates.

Purpose of the Study:

• To design and synthesize novel coumarin-based conjugating linkers for protein modification.
• To develop a site-specific protein labeling method with enhanced fluorogenic properties.
• To enable facile synthesis of protein-cargo conjugates for therapeutic applications.

Main Methods:

• Synthesis of two novel coumarin-based linkers, each featuring a dimaleimide and a terminal alkyne.
• Development of a protein labeling strategy using a dicysteine tag for site-specific alkyne introduction.
• Utilizing click chemistry (azide-alkyne cycloaddition) for cargo attachment and assessing fluorogenic properties.

Main Results:

• Successful synthesis of two novel linkers with a coumarin core, dimaleimide, and alkyne functionalities.
• The second linker design enabled highly fluorogenic and rapid site-specific protein labeling with fluorescence monitoring.
• Demonstrated sequential or inverse order of cargo attachment and protein conjugation via click chemistry.

Conclusions:

• Novel coumarin-based linkers offer versatile tools for site-specific protein modification and bioconjugation.
• The developed fluorogenic labeling method allows for real-time monitoring of protein conjugation.
• These linkers facilitate the efficient synthesis of protein-cargo conjugates for potential therapeutic use.