Fig. 2
Detection of fast local motions by 15N R1 and R1ρ relaxation experiments. 15N–1H CP-based HSQC of wt- (a) and D76N- (b) [2H, 13C, 15N] β-2 microglobulin with 100% reprotonation at the exchangeable sites recorded on an 800 MHz spectrometer at 60 kHz MAS rate (283 K, pH 5.5). All resonances were assigned using a set of experiments detailed in ref. 26. The color code (red for wt and blue for D76N β2m) is used for all the figures presented here. Site-specific 15N R1 (c) and R1ρ (d) relaxation rates of the two proteins were used to calculate the order parameters S2 (e) and the correlation time (f) with the model-free approach. The results of a 50 ns MD trajectory are plotted together with the experimental results in E (red and blue bundles). β2m secondary structures are plotted on top of the panels. Experimental error bars (s.d.) were obtained from 1000 Monte Carlo simulations
