Fig. 2.
Contrasting effects of the denaturing osmolyte urea and the counteracting osmolyte TMAO on α-synuclein dimensions. (A) and (B) show smFRET histogram data on α-synuclein TMAO and urea isothermal titrations, color-coded on the basis of fractional populations (red to blue representing high to low populations, respectively). Projections of the 3D contour plots onto the EFRET—TMAO/EFRET—urea planes are shown at the top for each panel. (C) and (D) present mean EFRET as functions of cosolvent concentrations. EFRET values were obtained by nonlinear least-squares (NLS) fitting of individual smFRET histograms to a Gaussian function. Solid lines are shown as guides.