Transfer of energy between fluorescent molecules

See also: Freight (homonymy)

The transfer of energy between fluorescent molecules or transfer of energy by resonance of the type Förster (FREIGHT, for the Acronym English " Fluorescent resonance energy transfer" or more rigorously " Förster resonance energy transfer") occurring between two fluorescent molecules close one is a quantum phenomenon to the other (distance ranging between ten and hundred Angstrom) and of which the Emission spectrum of the one (the molecule " donneuse") recover partially the Specter of excitation of the other (the molecule " acceptrice). When donneuse the D is excited by a photon, it can transmit its energy to the acceptrice has which then is found in a state excited and emits light. Concretely, by exciting D with his wavelength of excitation, one does not observe the intensity of fluorescent awaited, but a light output with the wavelength of emission of has . One can then evaluate the distance between the two molecules according to the effectiveness of the transfer of energy between the two molecules. (It should however be noted that the phenomenon of transfer of energy is not accompanied forcing by an emission of fluorescence of the acceptor)

Physical description of FREIGHT

The Fluorescence is the emission of a photon by the relieving of a beforehand excited molecule. The spectrum

Various methods of observation of FREIGHT

Methods using of measurements of luminous intensity

Comparison of the intensities of emission of the donor and the acceptor

Comparison of the intensity of emission of the donor before and after bleaching of the acceptor

Methods utlisants of measurements of lifespan of fluorescence

Examples of application of FREIGHT

Measurements of the distance between two molecules

Measurements of a biological interaction between two proteins

Drawn from a publication: Calmodulin Regulates Intracellular Trafficking off Epidermal Growth Factor Receptor and the MAPK Signaling Pathway, F. Tebar and Al, 2002

Measurements of a conformational change of a protein

Biological indicator

" CaMéléon"

Sensor of AMPc

See too

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