Figure 1.

Proline residues are abundant in IDPs/IDRs, and their ${}^{\mathrm{15}}\mathrm{N}$ resonances can be easily detected. They fall in a specific, isolated region of the 2D CON spectrum, as illustrated by the examples in the figure. From left to right: $\mathit{\alpha }$ -synuclein (140 aa, 4 % Pro; Bermel et al., 2006b), human securin (200 aa, 11 % Pro; Bermel et al., 2009), E1A (243 aa, 16 % Pro; Hošek et al., 2016), CBP-ID3 (407 aa 18 % Pro; Contreras-Martos et al., 2017), and CBP-ID4 (207 aa, 22 % Pro; Piai et al., 2016).