FRET in membrane biophysics: an overview

Abstract

Förster resonance energy transfer (FRET), in most applications used as a “spectroscopic ruler,” allows an easy determination of the donor-acceptor intermolecular distance. However, the situation becomes complex in membranes, since around each donor there is an ensemble of acceptors at non-correlated distances. In this review, state-of-the-art methodologies for this situation are presented, usually involving time-resolved data and model fitting. This powerful approach can be used to study the occurrence of phase separation (“rafts” or other type of domains), allowing their detection as well as size evaluation. Formalisms for studying lipid–protein and protein–protein interactions according to specific topologies are also addressed. The advantages and added complexity of a specific type of FRET (energy homotransfer or energy migration) are described, as well as applications of FRET under the microscope.

Resveratrol induces ordered domains formation in biomembranes: Implication for its pleiotropic action

“…FRET efficiency in the presence of increasing membrane effective concentrations of resveratrol was also plotted in supporting information ( Figure S1), where it can be seen that a lower membranar concentration produces a greater effect on phase separation in a more ordered membrane, such as the case of EPC:CHOL:SM. As already said, R 0 is the critical distance characteristic of a particular donor/acceptor pair of FRET probes which is also dependent on the surrounding lipid environment [37]. The R 0 for DPPE-NBD/DOPE-Rhod was estimated to be between 45 Å and 70 Å [42,43] for different lipid model systems, and more recently, FRET studies performed in POPC bilayers have also shown an effective R 0 of 49 Å [18].…”

“…The magnitude of R 0 is dependent on the spectral properties of the donor and acceptor dyes, but is also dependent on the lipid environment [37]. Therefore, the value of R 0 (in Å) observed in each membrane model system for NBD/Rhod pair should be experimentally calculated through the equation [38]:…”

Time-Resolved FRET -Based Approach for Antibody Detection – A New Serodiagnostic Concept

“…The level of light emitted from the acceptor fluorophore is proportional to the degree of donor-acceptor complex formation [4]. FRET between chromophores is characterized by Förster radius (R 0 ), the distance at which the efficiency of FRET is 50% [5]. This phenomenon has been applied, among others, to study of protein-protein interactions, antigen-antibody binding, ligand-receptor interactions, DNA hybridization and DNA-protein binding [2], [6]–[11].…”

Lateral Distribution of NBD-PC Fluorescent Lipid Analogs in Membranes Probed by Molecular Dynamics-Assisted Analysis of Förster Resonance Energy Transfer (FRET) and Fluorescence Quenching

“…Because of its strong intermolecular distance dependence (and therefore sensitivity to spatial distribution), Förster resonance energy transfer (FRET) has multiple applications in membrane biophysics, such as membrane protein mapping, lateral heterogeneity (membrane domains), determination of the transverse location (depth) of fluorescent residues/labels inside the membrane, protein/lipid selectivity (preference of a specific lipid for the protein vicinity), and membrane protein oligomerization [1], both in spectroscopic studies and, more recently, under the microscope [2]. Even though FRET is still commonly used as a qualitative indicator of chromophore proximity without accounting for its actual kinetics, full quantitative exploitation of its potential involves modeling of the FRET observables.…”