Figure 7: Mapping the LNnT-binding epitope using 2D STD-NMR spectroscopy.
(a) 2D TOCSY spectrum of LNnT (from 3.1 to 4.6 p.p.m.) is shown on the left panel with several cross-peaks assignment. Proton cross-peaks are labelled according to the nomenclature shown on the right panel. (b) 2D STD TOCSY spectrum of LNnT in the presence of GAL1 is represented on the left panel. The cross-peaks showing the highest intensity are circled and assignment is indicated. The circles are colour coded according to the monosaccharide they belong to: terminal galactose: magenta, N-acetylglucosamine: red, internal galactose: green, terminal glucose: blue. On the right panel, the significant relative STD signals observed are reported on the LNnT and are colour coded according to the colour scale shown above. The 100% STD signal corresponds to the resonance showing the highest intensity contribution in each experiment; all other STD signals are calculated accordingly. (c) 2D STD TOCSY of LNnT+GAL1+λ5-UR22-45 is shown on the left panel. On the right panel, the relative STD signals observed are reported on the LNnT as in b.
