TABLE 2.
Mass content of cardiolipin molecular species in lipid extracts of mouse liver
| [M-2H]2− | Major Species | Mass Content (Low) | Mass Content (High) |
|---|---|---|---|
| 697.470 | 18:2-18:2-16:1-16:1 | 0.02 ± 0.00 | |
| 698.458 | 18:2-18:2-16:1-16:0 | 0.02 ± 0.00 | |
| 699.480 | 18:2-18:1-16:1-16:0 | 0.02 ± 0.00 | |
| 700.479 | 18:2-18:1-16:0-16:0 | 0.04 ± 0.01 | |
| 710.465 | 18:2-18:2-18:2-16:1 | 0.32 ± 0.03 | 0.31 ± 0.02 |
| 711.474 | 18:2-18:2-18:2-16:0
18:2-18:2-18:1-16:1 |
0.07 ± 0.01 | 0.18 ± 0.05 |
| 712.485 | 18:2-18:1-18:1-16:1
18:2-18:2-18:1-16:0 |
0.11 ± 0.02 | 0.06 ± 0.02 |
| 713.497 | 18:2-18:1-18:1-16:0 | 0.06 ± 0.02 | |
| 722.482 | 18:2-18:2-18:2-18:3 | 0.12 ± 0.01 | |
| 723.485 | 18:2-18:2-18:2-18:2 | 2.92 ± 0.23 | 2.48 ± 0.11 |
| 724.489 | 18:2-18:2-18:2-18:1 | 1.06 ± 0.06 | 1.14 ± 0.07 |
| 725.494 | 18:2-18:2-18:1-18:1 | 0.29 ± 0.03 | 0.33 ± 0.05 |
| 726.500 | 18:2-18:2-18:1-18:0
18:2-18:1-18:1-18:1 |
0.04 ± 0.02 | |
| 734.465 | 20:4-20:4-18:2-16:1 | 0.03 ± 0.00 | 0.02 ± 0.01 |
| 735.475 | 20:4-18:2-18:2-18:2 | 0.08 ± 0.01 | 0.06 ± 0.01 |
| 736.492 | 20:3-18:2-18:2-18:2 | 0.20 ± 0.02 | 0.19 ± 0.02 |
| 737.500 | 20:2-18:2-18:2-18:2 | 0.15 ± 0.01 | 0.23 ± 0.04 |
| 738.509 | 20:1-18:2-18:2-18:2
20:2-18:2-18:2-18:1 |
0.09 ± 0.01 | 0.12 ± 0.00 |
| 739.510 | 20:1-18:2-18:2-18:1 | 0.09 ± 0.01 | 0.03 ± 0.01 |
| 747.511 | 22:6-18:2-18:2-18:2 | 0.08 ± 0.01 | 0.06 ± 0.00 |
| 748.513 | 22:5-18:2-18:2-18:2 | 0.04 ± 0.00 | 0.05 ± 0.01 |
| Total | 5.53 ± 0.38 | 5.58 ± 0.31 | |
| Mass and composition of linoleate | 18.42 ± 0.42 (83.3) | 18.26 ± 1.01 (81.8) |
Mouse hepatic lipids were extracted by a modified Bligh and Dyer procedure (21). The cardiolipin molecular species in the lipid extracts were identified using two-dimensional MS analyses, or by searching for m+1 isotopomers of doubly charged cardiolipin ions followed by two-dimensional MS analyses, or by searching for m+1 isotopomers of doubly charged cardiolipin ions followed by product ion analyses of these m+1 isotopomers when a QqQ instrument with low or high mass resolution or a QqTOF mass spectrometer was used. The data listed under Mass Content (Low) were quantitated using a two-step quantitation process with a QqQ instrument with a low mass resolution. The data listed under Mass Content (High) are the averaged results of those quantitated with a QqQ instrument using a high mass resolution setting using equation 1 in combination with the two-step quantitation process and those quantitated with a QqTOF mass spectrometer using equation 1 only. The results are expressed in nmol/mg protein and represent means ± SD of four different animals. Data in parentheses represent the percentage of linoleate in the cardiolipin pool. The molecular mass values listed in the left column were obtained with the QqTOF mass spectrometer. The ion peaks of cardiolipin molecular species that constitute <0.01 nmol/mg protein, as determined with the QqTOF mass spectrometer, were omitted.