Analysis of FRET signals in the presence of free donors and acceptors

Item Type:	Article
Title:	Analysis of FRET signals in the presence of free donors and acceptors
Creators Name:	Wlodarczyk, J. and Woehler, A. and Kobe, F. and Ponimaskin, E. and Zeug, A. and Neher, E.
Abstract:	A method for spectral analysis of Förster resonance energy transfer (FRET) signals is presented, taking into consideration both the contributions of unpaired donor and acceptor fluorophores and the influence of incomplete labeling of the interacting partners. It is shown that spectral analysis of intermolecular FRET cannot yield accurate values of the Foerster energy transfer efficiency E, unless one of the interactors is in large excess and perfectly labeled. Instead, analysis of donor quenching yields a product of the form Efdpa, where fd is the fraction of donor-type molecules participating in donor-acceptor complexes and pa is the labeling probability of the acceptor. Similarly, analysis of sensitized emission yields a product involving Efa. The analysis of intramolecular FRET (e.g., of tandem constructs) yields the product Epa. We use our method to determine these values for a tandem construct of cyan fluorescent protein and yellow fluorescent protein and compare them with those obtained by standard acceptor photobleaching and fluorescence lifetime measurements. We call the method lux-FRET, since it relies on linear unmixing of spectral components.
Keywords:	Algorithms, Biopolymers, Chemical Models, Computer Simulation, Fluorescence Resonance Energy Transfer
Source:	Biophysical Journal
ISSN:	0006-3495
Publisher:	Cell Press
Volume:	94
Number:	3
Page Range:	986-1000
Date:	1 February 2008
Official Publication:	https://doi.org/10.1529/biophysj.107.111773
PubMed:	View item in PubMed

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