Figure 5.

Series of 2D ¹³C-¹³C correlation spectra of uniformly ¹³C,¹⁵N-labeled rmMBP in the rmMBP-actin complex. In all experiments, the indirect and direct acquisition times were 7.6 and 12 ms, and the spectra were apodized with a π/2-shifted sine-squared window function before Fourier transformation. The first contour is cut at 4.5 times the noise floor and each subsequent contour level is multiplied by 1.15. The regions indicated by dashed rectangles are expanded in Fig. 6 for secondary structure analysis. (A and B) Aliphatic regions of DARR experiments collected at 274K and 255K, respectively, at 600 MHz. Both DARR spectra were acquired with 64 scans per t₁ point. (C) Aliphatic region of the SPC5₃ double-quantum correlation spectrum collected at 600 MHz, 248K, and with 56 scans per t₁ point. All crosspeaks in this spectrum are negative, indicating that they are all due to one-bond correlations. (D) Aliphatic region of TOBSY spectrum collected at 278K, at 800 MHz, with 128 scans per t₁ point.