Bioluminescence resonance energy transfer (BRET), results from a naturally occurring phenomenon, the resonance energy transfer between a luminescent enzymatic donor and a fluorescent protein acceptor. In BRET, the transfer efficiency is governed by the degree of spectral overlap, relative orientation and distance between the donor and acceptor. BRET typically occurs in the 1-10 nm range, comparable with the dimensions of biological macromolecules which makes BRET an ideal platform to study protein-protein interaction or structural changes in protein structure, in living cells.
BioSens-All™ biosensors are cellular BRET assays perfectly suited for mapping signal transduction pathways. The assays are based on non-radiative energy transfer between fusion proteins containing a bioluminescent luciferase (RLuc) and a green fluorescent protein (GFP). When the RLuc donor and GFP acceptor are in close proximity, energy created by the catalytic degradation of the coelenterazine derivative substrate is transferred from the luciferase to the GFP, which will then emit fluorescence at its characteristic wavelength.
Are based on protein–protein interactions modified by a signaling event. The G protein (heterotrimer) biosensor represents this biosensor structure.
Are based on the detection of intramolecular rearrangements of a sensor attached to both energy donor and acceptor. These rearrangements are promoted either by the binding of a second messenger or partner protein, a translocation event from the cytoplasm to the plasma membrane or a phosphorylation. For example the cAMP biosensor is unimolecular.