Detection of the homo- and hetero-interaction of proteins using fluorescence resonance energy transfer spectrum method

Fluorescence spectrometry based on fluorescence resonance energy transfer (FRET) principle is a simple but effective tool for investigating protein–protein interactions. In this paper, we report a spectrometry to quantify FRET efficiency based on our home-designed spectral probe system and spectral data-processing procedure. In our method, the fluorescence spectrum from each specimen is recorded at two wavelengths 454 and 502 nm. Least-squares linear fitting algorithm is applied directly to decompose the spectra of donor and acceptor under these two wavelengths to obtain FRET efficiency, which takes both spectral intensity and spectral profile into account compared with traditional three-step analysis. This system and the data-processing procedure enabled us to detect the homo-interaction and hetero-interaction of proteins in living cell.