Fig. 5. Aromatic and side-chain intramolecular contacts.
a The design variants TPPS and PYP with the same amino acid composition as yCTD but changed sequence. Swapped residues are shown in red. b Overlay of the aromatic regions of two-dimensional 1H-1H NOESY spectra of yCTD and its PYP and TPPS variants recorded in the dilute phase. Five regions of interest (ROI) were defined and used for signal integration. c, d Integrals of the NOE peaks (arbitrary units; AU) extracted from the spectra in panel (b). The integrals are classified into two vertical categories corresponding to the chemical shift of the aromatic protons in positions epsilon (c) and delta (d). The stacks of each graph are divided into the five horizontal regions of chemical shifts (δ; vertical scale) indicated graphically in (b).