Fluorescence resonance energy transfer in studies of inter-chromophoric distances in biomolecules

Fluorescence resonance energy transfer (FRET) is a technique widely used in studies of interchromophoric distances in biomolecules such as peptides, pro­teins and nucleic acids. FRET is especially useful in determination of confor­mational changes caused by a solvent, presence of denaturing agents, diffusion and other external factors. Precision of interchromophoric distances obtained using the FRET technique is comparable with that of low-resolution X-ray diffraction and NMR data. Comparison of FRET results with the crystal struc­ture for several proteins is reviewed. Moreover, the effect of the orientation factor K2 value on FRET results and determinants of k2 are discussed.