Relationship between soluble (Csoluble) and total concentrations (Ctotal). (A) Csoluble versus Ctotal of TMR-Aβ fibrils in 0–6 M GdnCl; open circles represent the data and solid lines are linear fits. Soluble peptide concentrations were calculated from TMR fluorescence. (B) Soluble fraction (Csoluble/Ctotal) as a function of GdnCl concentration. Clearly, fraction dissolved (i.e., Csoluble/Ctotal) is independent of the total concentration of the amyloids. Total concentrations of amyloids used here are 25, 50, 99, 197, and 389 nM. To see this figure in color, go online.