FIGURE 6.

NMR characterization of residual structure in monomeric H50Q. A, overlay of ¹H,¹⁵N heteronuclear single quantum coherence spectroscopy spectra of WT (blue) and H50Q (red) α-Syn. Arrows highlight cross-peaks that exhibit large chemical shift changes between the WT and the variant. B, amide chemical shift differences between WT and H50Q α-Syn, calculated as the weighted combination Δδ_NH = (Δδ_H² + (Δδ_N/5)²)^½. Residue 50 is highlighted with an asterisk (*). C, chemical shift perturbations of HN, N, HA, C, CA, and CB resonances in H50Q. Glycine HA chemical shifts are reported as the averages of both chemical shifts. D, secondary structure populations of WT (dashed lines) and H50Q (solid lines) calculated from backbone chemical shift data using the δ2D algorithm (24).