Figure 1.

Terahertz fingerprint of LLPS of FUS. (A) Schematic drawing of the MBP-FUS and MBP-FUS-EGFP constructs is given. The constructs contain a His₆ tag (violet) for purification and two TEV cleavage sites (red) to cleave off MBP and the His₆ tag. FUS comprises the PLD (dark blue) and RBD domains (light blue). The Y to S substitutions are indicated as red lines below the PLD domain. (B) Microscopic images (50 × 50 μm; scale bar, 10 μm) of the protein samples (10 μM) are shown. The inset left of the image represents the corresponding sample analyzed by SDS-PAGE and Coomassie brilliant blue staining. Images of MBP-FUS were taken using brightfield illumination. (C) Averaged ATR-FTIR Δα spectra (50–650 cm⁻¹) of protein samples measured 60 min after deposition on the ATR crystal surface are shown. On the left side, we show Δα spectra (50–650 cm⁻¹) of samples that do not undergo LLPS, and on the right-hand side, spectra of samples after LLPS. The average error of all ATR-FTIR measurements is 5 cm⁻¹. To see this figure in color, go online.