Table I. Target proteins and their signature peptides.
Both [12C] and [13C] versions of monitor peptides were synthesized. Uniformly labeled amino acids are indicated in boldface type.
| Protein | Source | MW (kDa) | Signature Peptide | MH+(mono) | Z (Q1) | MRM Transitionsb |
|
|---|---|---|---|---|---|---|---|
| Q1 | Q3 | ||||||
| Aprotinin | bovine lung | 6.4 | AGLCamcQTFVYGGCamcRa | 1488.7 | 2 | 744.8 | 858.3, 959.4, 1087.5 |
| AGLCamcQTF[13C5]VYGGCamcRa | 1493.7 | 2 | 747.3 | 863.4, 964.4, 1092.5 | |||
|
| |||||||
| Leptin | mouse | 10 | INDISHTQSVSAK | 1399.7 | 3 | 467.2 | 543.2, 586.8, 643.8 |
| INDISHTQS[13C5]VSAK | 1404.7 | 3 | 468.9 | 543.2, 589.3, 646.3 | |||
|
| |||||||
| Myoglobin | Horse heart | 17 | LFTGHPETLEK | 1271.7 | 3 | 424.6 | 506.2, 579.7, 716.3 |
| LFTGHPET[13C6]LEK | 1277.7 | 3 | 426.6 | 509.2, 582.8, 722.4 | |||
|
| |||||||
| Myelin Basic Protein | bovine | 18 | HGFLPR | 726.4 | 2 | 363.7 | 385.2, 532.3, 589.3 |
| HGF[13C6]LPR | 732.4 | 2 | 366.7 | 391.2, 538.3, 595.3 | |||
| YLASASTMDHAR | 1322.6 | 3 | 441.5 | 488.2, 523.7, 817.3 | |||
| Y[13C6]LASASTMDHAR | 1328.6 | 3 | 443.5 | 488.2, 523.7, 817.3 | |||
|
| |||||||
| Prostate Specific Antigen | human | 30 | IVGGWECamcEka | 1077.5 | 2 | 539.3 | 808.3, 865.3, 964.4 |
| I[13C5]VGGWECamcEKa | 1082.5 | 2 | 541.7 | 808.3, 865.3, 969.4 | |||
| LSEPAELTDAVK | 1272.7 | 2 | 636.7 | 775.4, 846.4, 943.4 | |||
| LSEPAE[13C6]LTDAVK | 1278.7 | 2 | 639.7 | 781.3, 852.5, 949.4 | |||
|
| |||||||
| Peroxidase | Horse Radish | 48 | DTIVNELR | 959.5 | 2 | 480.3 | 531.2, 630.3, 743.4 |
| DTIVNE[13C6]LR | 965.5 | 2 | 483.3 | 537.3, 636.3, 749.4 | |||
| SSDLVALSGGHTFGK | 1475.7 | 3 | 492.6 | 703.3, 790.3, 974.5 | |||
| SSDLVA[13C6]LSGGHTFGK | 1481.8 | 3 | 494.6 | 703.3, 790.3, 980.5 | |||
a
Cysteines are synthesized as carbamidomethyl cysteines.
b
All three transitions were monitored. However, only the transition in bold was used to determine LOQ.