Fig. 4: OLF^WT chemical unfolding tracked by NMR.

a ¹H-¹⁵N TROSY-HSQC data of OLF^WT as a function of urea concentration shows a transition from well-folded to denatured. b Principal component analysis of the data in panel a quantifies the midpoint of urea unfolding, 2.7 ± 0.3 M. c CSP of retained assignable resonances mapped onto OLF^WT structure from 1 M (top) and 2 M (bottom) spectra from panel (a) (mustard and blue spectra, respectively). These data identify regions of OLF that retain WT-like structure as they initially transition towards unfolding. At urea concentrations >2 M, the unfolded state is dominant and limits the ability to confidently map assignments and track CSP. Unassigned residues are in grey. See also Supplementary Figs. 7 and 8. Source data are provided as a Source Data file.