Monitoring Dynamic Conformations of a Single Fluorescent Molecule Inside a Protein Cavity

Area of Science:

• Structural Biology
• Biophysics
• Nanotechnology

Background:

• Fluorescence nanoscopy and single-molecule techniques are advancing structural biology.
• Dynamic structural measurements in physiological conditions are crucial but challenging.

Purpose of the Study:

• To determine fluorophore orientation within a protein cavity using advanced microscopy.
• To establish a realistic interplay between experimental data and simulations for structural biology.
• To enable dynamic structural measurements of nanoscopic biological systems.

Main Methods:

• Combined single-molecule localization microscopy and polarization-dependent single-molecule excitation.
• Utilized protein engineering to orient fluorophores within a protein cavity.
• Validated experimental findings with molecular dynamics simulations.

Main Results:

• Successfully determined fluorophore orientation and hydrogen bond interactions within a protein cavity.
• Observed conformations aligned well with molecular dynamics simulations.
• Monitored conformational jumps with 3° precision and second-level time resolution.

Conclusions:

• This methodology offers a new approach for dynamic structural measurements in biological systems.
• It facilitates a realistic interplay between experiments and simulations for identifying stable conformations and interactions.
• The technique holds significant potential for studying nanoscopic biological systems under physiological conditions.