Fig 3. Medium of HEK293-ANKH^wt cells contains large amounts of citrate, succinate and malate.

LC/MS-based global metabolite profiling was applied to 24-hour medium samples of HEK293 parental, HEK293-ANKH^wt and HEK293-ANKH^L244S cells. The relative abundance of masses corresponding to citrate (A), malate (B) and succinate (C) were determined. Authentic standards were used to confirm the identity of the Krebs-cycle intermediates. Using an enzymatic assay, citrate concentrations were followed for 24 hours in (D). Data are expressed as mean +/- SD of an experiment performed in triplicate. Statistical significance was determined by one-way ANOVA (panels A, B and C) or two-way-ANOVA (panel D). * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001.