A flexible approach to assess fluorescence decay functions in complex energy transfer systems.

Authors:
Christoph Roethlein
Christoph Roethlein
University of Potsdam
Markus S Miettinen
Markus S Miettinen
Freie Universität Berlin
Zoya Ignatova
Zoya Ignatova
University of Potsdam
Germany

BMC Biophys 2015 3;8. Epub 2015 Apr 3.

Biochemistry and Biology, University of Potsdam, Potsdam, Germany ; Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany.

Background: Time-correlated Förster resonance energy transfer (FRET) probes molecular distances with greater accuracy than intensity-based calculation of FRET efficiency and provides a powerful tool to study biomolecular structure and dynamics. Moreover, time-correlated photon count measurements bear additional information on the variety of donor surroundings allowing more detailed differentiation between distinct structural geometries which are typically inaccessible to general fitting solutions.

Results: Here we develop a new approach based on Monte Carlo simulations of time-correlated FRET events to estimate the time-correlated single photon counts (TCSPC) histograms in complex systems. This simulation solution assesses the full statistics of time-correlated photon counts and distance distributions of fluorescently labeled biomolecules. The simulations are consistent with the theoretical predictions of the dye behavior in FRET systems with defined dye distances and measurements of randomly distributed dye solutions. We validate the simulation results using a highly heterogeneous aggregation system and explore the conditions to use this tool in complex systems.

Conclusion: This approach is powerful in distinguishing distance distributions in a wide variety of experimental setups, thus providing a versatile tool to accurately distinguish between different structural assemblies in highly complex systems.

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http://dx.doi.org/10.1186/s13628-015-0020-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4403788PMC
April 2015
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