Skip to main content
. 2018 Mar 1;114(4):870–884. doi: 10.1016/j.bpj.2017.12.025

Figure 2.

Figure 2

FRET efficiency histograms obtained from free diffusion experiments for Aβ40 (A) and Aβ42 (B). (A and B) Apparent (uncorrected) FRET efficiencies were calculated using the photons collected in 2 ms bins (≥30 photons). “No tag” stands for the protein samples without AviTag and linker and AviTag represents Avi-Aβ. Blue dashed lines indicate the center of the FRET efficiency peak (Gaussian fit) of Avi-Aβ42 measured in PBS and are drawn for the comparison of the FRET efficiencies between different constructs. Red dashed lines indicate the center of the peaks of individual constructs measured in PBS. The FRET efficiency decreases gradually as the urea concentration is increased, indicating the expansion of disordered proteins. (C) Apparent FRET efficiency histograms for Aβ40 (top) and Aβ42 (bottom) without AviTag in PBS with the addition of 1 M NaCl. Red dashed lines indicate the center of the peaks of the histograms measured in PBS. (D) FRET efficiency changes as a function of urea concentration. FRET efficiencies were corrected for background, donor leak, and γ-factor. Square symbols are the data collected in PBS with an additional 1 M NaCl. To see this figure in color, go online.