Supramolecular latching system based on ultrastable synthetic binding pairs as versatile tools for protein imaging

Area of Science:

• Supramolecular Chemistry
• Chemical Biology
• Bioimaging

Background:

• Traditional protein-based binding pairs for bioimaging face limitations.
• Development of synthetic, non-protein-based alternatives is crucial for advancing protein analysis.

Purpose of the Study:

• To establish ultrastable synthetic binding pairs for protein imaging.
• To overcome limitations associated with current protein-based bioimaging techniques.
• To demonstrate a controllable supramolecular latching system for selective protein visualization.

Main Methods:

• Utilized cucurbit[7]uril (CB[7]) as a synthetic host molecule.
• Developed adamantyl- (AdA) and ferrocenyl-ammonium (FcA) as guest molecules for protein labeling.
• Employed cyanine 3-conjugated CB[7] (Cy3-CB[7]) for fluorescence imaging.
• Demonstrated system controllability using a stronger competitor guest at low temperatures.

Main Results:

• Achieved ultrastable synthetic binding pairs between CB[7] and AdA/FcA.
• Successfully visualized AdA- or FcA-labeled proteins using Cy3-CB[7] for clear fluorescence imaging.
• Demonstrated selective detachment of Cy3-CB[7] from cell surface proteins while maintaining binding to cytosolic proteins.
• Achieved spatially conditional visualization of target proteins.

Conclusions:

• The developed synthetic supramolecular system offers a robust and controllable alternative to protein-based bioimaging tools.
• This non-protein-based approach presents inherent advantages for protein analysis and imaging.
• The system shows significant potential for future applications in bioimaging and chemical biology.