Table IV. Detection of isotopically labeled APGs.
Concentration Applied | Substrates | Compound | Products |
|
---|---|---|---|---|
Unlabeled | Labeled | |||
mm | % | |||
10 | l-Leu | M3 | 100a | 0b |
50 | l-Leu | M3 | 100 | 0 |
10 | l-Leu-13C6 | M3 | 100 | 19.7 ± 1.3 |
50 | l-Leu-13C6 | M3 | 100 | 78.7 ± 6.3 |
10 | l-Ile | M1 | 100 | 0 |
50 | l-Ile | M1 | 100 | 0 |
10 | l-Ile-13C6 | M1 | 100 | 15.9 ± 5.3 |
50 | l-Ile-13C6 | M1 | 100 | 40.4 ± 0.3 |
10 | l-Val | M2 | 100 | 0 |
50 | l-Val | M2 | 100 | 0 |
10 | l-Val-2,3,4,4,4,5,5,5-D8 | M2 | 100 | 22.9 ± 4.7 |
50 | l-Val-2,3,4,4,4,5,5,5-D8 | M2 | 100 | 48.0 ± 24.9 |
Integrated peak areas of pseudomolecular ions m/z –371, –371, and –357 (after application of l-Leu, l-Ile, and l-Val, respectively) were set to 100%. b Percentages of labeled products were calculated from the integrated peak areas of the pseudomolecular ions of isotopically labeled products m/z –376, –376, and –364 (after application of l-Leu-13C6, l-Ile-13C6, and l-Val-2,3,4,4,4,5,5,5-D8, respectively).