Figure 1.

¹⁵N/¹H HSQC spectra of ¹⁵N uniformly labeled ubiquitin at various pressures from 30 to 3,700 bar at 0°C. The protein is dissolved to a concentration of 2.0 mM in 30 mM acetate buffer (95% ¹H₂O/5% ²H₂O, pH 4.5). Chemical shifts of individual crosspeaks from the folded part of the protein at 30 bar were identical with those at 1 bar, which had been assigned to specific amino acid residues by Wang et al. (30). Crosspeak of Ile-36 showing preferential broadening below 1,500 bar is encircled. The crosspeak of Val-70 is marked with an arrow.