Single-photon smFRET. I: Theory and conceptual basis

Area of Science:

• Biophysics
• Chemical Physics
• Computational Biology

Background:

• Single-molecule Förster resonance energy transfer (smFRET) is a powerful technique for studying molecular dynamics.
• Existing smFRET analysis tools often struggle with complex experimental realities like photophysics and detector artifacts.
• A unified framework is needed to accurately interpret single-photon smFRET data.

Purpose of the Study:

• To present a unified conceptual framework and software package for single-photon smFRET analysis.
• To address key physical complexities inherent in smFRET experiments.
• To provide a robust method for analyzing smFRET data from both continuous and pulsed illumination.

Main Methods:

• Leveraging Bayesian nonparametrics (BNP) for smFRET analysis.
• Developing a hidden Markov model with second-order structure.
• Integrating solutions for fluorophore photophysics, kinetics, detector artifacts, background emissions, and an unknown number of states.

Main Results:

• A unified framework, BNP-FRET, is established for single-photon smFRET analysis.
• The framework effectively handles complex experimental factors.
• The methodology is applicable to both continuous and pulsed illumination experiments.

Conclusions:

• BNP-FRET offers a comprehensive solution for advanced smFRET data analysis.
• This framework enhances the accuracy and scope of smFRET studies.
• Future work will detail parameter inference for continuous and pulsed illumination.