FIGURE 5.
FRET distance measurement between donor and acceptor labels. A, diagram of the experimental setup for FRET distance measurement. Donor fluorescence intensity in the absence of acceptor, FD was measured by adding only the europium cryptate conjugate to either the IN heterodimer mixture or the negative control peptide in the presence or absence of compound. Donor fluorescence intensity in the presence of acceptor, FDA, was measured by adding the europium cryptate conjugate and the XL665 conjugate to either the IN heterodimer mixture or the negative control peptide in the presence or absence of compound. B, FRET distance measurement between europium cryptate and XL665 from the ends of a negative control peptide. C, FRET distance measurement between europium cryptate and XL665 from two monomers of a heterodimer. The mean FRET efficiency was calculated from three independent experiments done in octuplicates.