화학공학소재연구정보센터
International Journal of Molecular Sciences, Vol.15, No.12, 22518-22538, 2014
Intrinsic Tryptophan Fluorescence in the Detection and Analysis of Proteins: A Focus on Forster Resonance Energy Transfer Techniques
Frster resonance energy transfer (FRET) occurs when the distance between a donor fluorophore and an acceptor is within 10 nm, and its application often necessitates fluorescent labeling of biological targets. However, covalent modification of biomolecules can inadvertently give rise to conformational and/or functional changes. This review describes the application of intrinsic protein fluorescence, predominantly derived from tryptophan (lambda(EX) similar to 280 nm, lambda(EM) similar to 350 nm), in protein-related research and mainly focuses on label-free FRET techniques. In terms of wavelength and intensity, tryptophan fluorescence is strongly influenced by its (or the protein's) local environment, which, in addition to fluorescence quenching, has been applied to study protein conformational changes. Intrinsic Frster resonance energy transfer (iFRET), a recently developed technique, utilizes the intrinsic fluorescence of tryptophan in conjunction with target-specific fluorescent probes as FRET donors and acceptors, respectively, for real time detection of native proteins.