Fig. 3

SIRM analysis of fumarate and citrate in UOK262 cells by IC-FTMS under different conditions. Metabolites were resolved and quantified as described in the “Methods” section, and the absolute concentrations and fraction enrichments are given for both UOK262WT (WT) and UOK262FH−/− (KO) under different treatment conditions. Means and standard errors are shown. An unpaired two-tailed t test was used for statistical comparisons. Cx_Ny are isotopologues that contain x¹³C and y¹⁵N atoms. a Absolute amounts of total fumarate in μmole/g. UOK262 p = 0.0158 for +Gln + Asn versus +Gln-Asn; p = 0.102 for +Gln + Asn versus -Gln + Asn: WT p = 0.0044 for +Gln + Asn versus +Gln-Asn; p = 0.033 for -Gln + Asn versus +Gln + Asn. b Fractional ¹³C enrichment in fumarate isotopologues. Upper: WT versus KO for ¹³C¹⁵N Asn alone and for ¹³C¹⁵N Gln alone. WT ¹³C¹⁵N Asn, KO ¹³C¹⁵N Asn, WT ¹³C¹⁵N Gln, KO ¹³C¹⁵N Gln. Lower: WT versus KO for ¹³C¹⁵N Asn with ¹²C¹⁴N (unlabeled) Gln and for ¹²C¹⁴N (unlabeled) Asn + ¹³C¹⁵N Gln. WT ¹³C¹⁵N Asn plus ¹²C¹⁴N Gln, KO ¹³C¹⁵N Asn plus ¹²C¹⁴N Gln, WT ¹²C¹⁴N Asn plus ¹³C¹⁵N Gln, KO ¹²C¹⁴N Asn plus ¹³C¹⁵N Gln. c Absolute amounts of total citrate in μmole/g. UOK262 p = 0.607 for +Q + N versus +Q-N; p = 0.0083 for +-Q + N versus +Q + N: WT p = 0.0723 for +Q + N versus +Q-N; p = 0.452 for +-Q + N versus +Q + N. d Fractional ¹³C enrichment in citrate. WT Gln versus KO Gln p = 0.0082; WT Gln + Asn vs KO Gln + Asn p = 0.0002. Upper: WT versus KO for ¹³C¹⁵N Asn alone and for ¹³C¹⁵N Gln alone. WT ¹³C¹⁵N Asn, KO ¹³C¹⁵N Asn, WT ¹³C¹⁵N Gln, KO ¹³C¹⁵N Gln. Lower: WT versus KO for ¹³C¹⁵N Asn with ¹²C¹⁴N (unlabeled) Gln and for ¹²C¹⁴N (unlabeled) Asn + ¹³C¹⁵N Gln. WT ¹³C¹⁵N Asn plus ¹²C¹⁴N Gln, KO ¹³C¹⁵N Asn plus ¹²C¹⁴N Gln, WT ¹²C¹⁴N Asn plus ¹³C¹⁵N Gln, KO ¹²C¹⁴N Asn plus ¹³C¹⁵N Gln