Figure 16.

NMR spectroscopy of liquid–liquid phase separation of the repeat domain of tau. (a, b) Superposition of 2D ¹H-¹⁵N HSQC (a) and 2D CON (b) spectra of K18 in the monomeric dispersed state (5 °C, black) and the droplet phase (37 °C, red). To avoid contributions of solvent exchange to NMR signal broadening in ¹H-¹⁵N correlation spectra, D₂O was placed into a separate capillary tube (insert in a). (c) Superposition of CON spectra of K18 recorded at 37 °C in the absence (−hex, red) and presence (+hex, blue) of 3% 1,6-hexanediol, which rapidly dissolved K18 droplets (e). (d) DIC microscopy demonstrates K18 droplet formation at 37 °C. (e) Time-dependent dissolution of K18 droplets in the presence of 3% 1,6-hexanediol observed by DIC microscopy. Reproduced from ref (220) with permission from the Royal Society of Chemistry.