Fig. 3.

Tyr ε* His δ2 region of an aromatic ¹H¹³C-TROSY-HSQC of FKBP12. Signals arising from a 2-¹³C₁-glucose labeled sample are shown in black, while signals from a 1-¹³C₁-erythrose labeled sample are shown in red. His δ2 signals are broadened because ¹⁵N was not decoupled. Asterisk represents an averaged signal of position 1 and 2 because of fast exchange of the aromatic rings on the NMR time-scale