Fig. 4: D-Glucose versus 2,5-AHM coupling in PfHT1.

a, Left: STD-derived epitope mapping of the PfHT1:D-glucose proton interaction degree is shown on the structure of D-glucose by color from the highest (red) to lowest (beige). The STD/off-resonance ratio of the H2 β-proton, which was the highest value of all protons, was set as 100% for the normalization of the other proton resonance intensities. Right: STD (red) and ¹H spectra (black) of D-glucose (500 µM) in the presence of PfHT1-GFP reconstituted into liposomes. The spectral region of the H1 proton is not shown for clarity. b, Left: structures of D-fructofuranose (top) and 2,5-AHM (bottom) with protons producing STD signals shown on red background. Right: corresponding STD (red) and ¹H spectra (black) in the presence of PfHT1-GFP reconstituted into liposomes. c, Sugar binding site in the crystal structure of PfHT1 in complex with the sugar 2,5-AHM (left) and in comparison the coordination of D-glucose (right), determined previously (PDB 6RW3); sugar binding site residues and ligands are shown as sticks, hydrogen bond interactions indicated by dashed lines and protein as cartoon (as in Fig. 1b). Insert shows the overlapping binding position of these carbohydrates following superimposition of the two structures.