FIGURE 17.

CIU and melting data for WT-, CT-, and FT₂-TTR. CIU heatmaps of (A) WT, (B) C-terminal tagged (CT), and (C) dual flag tagged (FT₂) show that FT₂ tag increases gas- and solution-phase stability of TTR and alters its unfolding pathway in the gas phase as a third intermediate was observed in CIU plot. (D) Solution stability was measured using I50 values corresponding to the energy required to dissociate 50 percent of the tetramer. T₄ was used as a control as it is known that it enhances the solution stability of TTR. (E) I50 values for WT-, CT-, and FT₂-TTR were plotted as a function of temperature, demonstrating slightly higher stability of FT₂-TTR at room temperature which diminishes at higher temperatures. Reproduced from Shirzadeh et al. (2020). CIU, collision-induced unfolding; TTR, transthyretin; WT, wild-type.