Fig. 4.

Quantitative analysis of the concentration dependence of ¹⁵N-relaxation dispersion profiles and exchange-induced shifts for htt^NTQ₇. Representative (A) ¹⁵N-CPMG relaxation dispersion profiles at 900 MHz (Top) and 600 MHz (Bottom) at three concentrations (1, 0.75, and 0.4 mM), (B) ¹⁵N-R_1ρ relaxation dispersion profiles at 800 and 600 MHz at a concentration of 1 mM, and (C) ¹⁵N-δ_ex exchange-induced chemical shifts (Top) and ${}^{15}\mathrm{N}-R_2^{1\mathrm{kHz}}$ (Bottom) at 800 MHz. The experimental data, recorded at 5 °C, are shown as circles. The best-fit curves from a global fit to the kinetic model shown in Fig. 5 are represented by the continuous lines. The relaxation dispersion data were recorded on a ¹³Cα/¹⁵N-labeled sample, while the exchange-induced shift and $R_2^{1kHz}$ data were recorded on a uniformly ¹³C/¹⁵N-labeled sample.