Fret-based Proximity Assay
Fret-based Proximity Assay - Related Videos
19:05
Measuring TCR-pMHC Binding In Situ using a FRET-based Microscopy Assay
0 Views •
Cited by 9 •
2015
This manuscript describes how to conduct (single molecule) Förster Resonance Energy Transfer (FRET)- based assays to measure the binding dynamics between T-cell antigen receptor (TCR) and antigenic peptide-loaded MHC molecules as they occur within the immunological synapse of a T-cell in contact with a functionalized planar supported lipid bilayer.
03:32
Amplified Luminescent Proximity Homogeneous Assay: A Bead-Based Proximity Assay to Screen Small Molecules Inhibiting Protein-Protein Interactions
0 Views •
2025
In this video, we demonstrate the amplified luminescent proximity homogeneous assay—a bead-based proximity assay. It utilizes homogeneously-sized acceptor and donor beads, immobilized with two proteins that tend to interact to screen potential small molecules inhibiting protein interactions.
09:12
G Protein-selective GPCR Conformations Measured Using FRET Sensors in a Live Cell Suspension Fluorometer Assay
0 Views •
Cited by 4 •
2016
Simple methods to detect the selective activation of G proteins by G protein-coupled receptors remain an outstanding challenge in cell signaling. Here, Fӧrster resonance energy transfer (FRET) biosensors have been developed by pairwise tethering a GPCR to G protein peptides to probe conformational changes at controlled concentrations in live cells.
09:47
FRET Imaging in Three-dimensional Hydrogels
0 Views •
Cited by 3 •
2016
Förster resonance energy transfer (FRET) imaging is a powerful tool for real-time cell biology studies. Here a method for FRET imaging cells in physiologic three-dimensional (3D) hydrogel microenvironments using conventional epifluorescence microscopy is presented. An analysis for ratiometric FRET probes that yields linear ratios over the activation range is described.
11:27
Studying DNA Looping by Single-Molecule FRET
0 Views •
Cited by 13 •
2014
This study presents a detailed experimental procedure to measure looping dynamics of double-stranded DNA using single-molecule Fluorescence Resonance Energy Transfer (FRET). The protocol also describes how to extract the looping probability density called the J factor.
FAQs
When the labeled molecules move within a few nanometers, excitation energy can pass from the donor fluorophore to the acceptor. That transfer changes the fluorescence measured from the pair, so a signal shift reports a change in relative proximity. The readout therefore provides nanoscale information about molecular rearrangements rather than merely indicating that both labels are present.
A conformational change can alter the distance between the donor- and acceptor-labeled positions on a molecule or between interacting molecules. Because transfer depends on nanoscale separation, the resulting fluorescence change can follow structural movement as it occurs. This makes the assay useful for examining receptor activation and other dynamic biochemical events, not only stable protein binding.
No. A proximity signal indicates close approach, but by itself it describes nanoscale proximity rather than establishing the full nature of an interaction. Researchers can use it to monitor protein binding while interpreting signal changes in relation to the biological question and labeling arrangement. This distinction matters when proximity results from activation-related rearrangement or cellular organization.
First, label the molecules of interest with donor and acceptor fluorophores. Then excite the donor and measure the resulting fluorescence signal from the labeled sample. Tracking that readout over time allows researchers to identify changes in proximity associated with protein binding, receptor activation, or structural rearrangement.
The same distance-sensitive strategy can be applied to living cells or to purified samples, allowing researchers to examine molecular behavior in different biological settings. In cells, measurements can inform studies of signaling pathways and cellular organization. In purified samples, the assay can follow protein binding or structural changes within the sample.
It is particularly useful when the question concerns a changing relationship between labeled molecules. Applications supported by the method include monitoring protein binding, receptor activation, molecular conformational changes, signaling pathways, cellular organization, and other dynamic biochemical processes. Its real-time, nanoscale readout helps connect a fluorescence change with molecular events that shift proximity during biological activity.