Table 2.
Methionine labeling with deuterated serine
MEFs were plated in triplicate in 10-cm dishes at a density of 1 × 106 cells per dish and were grown in labeling media for 4 days as described under “Experimental procedures.” Incorporation of the deuterium label into methionine was measured by LC-MS. Means of triplicate determinations ± S.D. are shown. M = unlabeled methionine, D1 = methionine + 1 deuteron, D2 = methionine + 2 deuterons. p values were calculated using two tailed t tests.
| Fraction of total (M + D1 + D2) |
Fraction of labeled (D1 + D2) |
||||
|---|---|---|---|---|---|
| D1 | D2 | D1 + D2 | D1 | D2 | |
| MTHFD1L+/+ | 0.18 ± 0.008 | 0.020 ± 0.01 | 0.20 ± 0.009 | 0.90 ± 0.05 | 0.10 ± 0.05 |
| MTHFD1L−/− | 0.033 ± 0.001 | 0.092 ± 0.009 | 0.12 ± 0.008 | 0.27 ± 0.03 | 0.73 ± 0.03 |
| p value | 6.70E-06 | 0.0011 | 5.80E-04 | 6.00-05 | 6.00E-05 |