Fig. 2. Overlay of 2D 1H–1H TOCSY NMR spectra (500 MHz) of MNEI (red) and Y65R (blue) at pH 3.3 (panel A) and pH 5.1 (panel B). All spectra were recorded using 2 mM
protein samples in 20 mM sodium-phosphate buffer at 35 C. Residues most affected from the mutation of Y65 of MNEI into R65 in Y65R are also marked (residues V64, Y65,
A66 and D68 are in black while R65 is in blue). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)