Figure 5. XMetD is an antagonist of insulin dependent Akt and Erk phosphorylation. (A) CHO-hINSR cells (B isoform) were preincubated for 30 min at 37 °C with a wide range of XMetD concentrations from 0 to 3333 nM followed by a 10 min incubation with increasing concentrations of insulin. Phosphorylation of Akt was measured using an electrochemiluminescence based assay. Mean of duplicate determinations are shown. (B) Insulin EC₅₀ values (from Fig. 5A) were determined for each concentration of XMetD and plotted as a function of XMetD concentration. Mean of duplicate determinations are shown. (C) CHO-hINSR cells (B isoform) were preincubated for 30 min at 37 °C with 333 nM of either XMetD or control IgG followed by a 10 min incubation with increasing concentrations of insulin. Phosphorylation of Erk was measured using an electrochemiluminescence based assay. Mean ± SD of triplicate determinations are shown.