Fig. 2: Characterization of rGLUT5 and inhibitor design.

a The competitive uptake of ¹⁴C-d-fructose by rGLUT5 in proteoliposomes prepared using brain-fraction-seven in the absence (white bar) and presence (black bars) of the non-labeled sugars with structures shown Supplementary Fig. 2a. Non-specific ¹⁴C-d-fructose uptake was estimated from decay activity recorded from liposomes without protein (red bar). Error bars indicate mean ± s.e.m. of n = 3 independent experiments. b As in a, with structures of non-labeled sugars shown in Supplementary Fig. 2b. c Uptake of ¹⁴C-d-fructose (black bars) and ¹⁴C-d-glucose (gray bars) by WT rGLUT5 and variants, in proteoliposomes prepared using brain-fraction-seven. Error bars indicate mean ± s.e.m. of n = 3 independent experiments. d Competitive uptake of ¹⁴C-d-fructose by rGLUT5 in proteoliposomes prepared using brain-fraction-seven with some of the first-generation inhibitors at 100 µM, activity data for the other compounds are shown in supplementary Fig. 3b, structures of the respective inhibitors within this work in Supplementary Fig. 3a and Supplementary Fig. 4. Reported MSNBA inhibitor was included for comparison³⁹. C2 compound competes mildly with ¹⁴C-d-fructose (empty bar with orange border). The structure of all compounds is shown in Supplementary Fig. 3a. Errors bars indicate the range of two independent experiments. e Commercially available derivatives of C2 were tested as in (d), and the most potent competitor for ¹⁴C-d-fructose is H2 (empty bar with orange border). The structure of all compounds is shown in Supplementary Fig. 3a. Error bars indicate mean ± s.e.m. of n = 3 independent experiments.