Table 1. Mass spectrometry parameters for the SRM assays of ubiquitination sites of STAT3 (1-130).
| Signature peptides | Ubiquitination site | Q1, m/z | Q3, m/z | CE (V) | Precursor, Z | Product, Z | ion type |
|---|---|---|---|---|---|---|---|
|
| |||||||
| IK[Ubiquitin]QFLQSR | Lys87 | 378.5524 | 503.2931 | 20 | 3 | 1 | y4 |
| 378.5524 | 650.3615 | 20 | 3 | 1 | y5 | ||
| 378.5524 | 778.42 | 20 | 3 | 1 | y6 | ||
| 378.5524 | 1020.558 | 20 | 3 | 1 | y7 | ||
| 378.5524 | 1133.642 | 20 | 3 | 1 | y8 | ||
| 567.3249 | 650.3615 | 23 | 2 | 1 | y5 | ||
| 567.3249 | 778.42 | 23 | 2 | 1 | y6 | ||
| 567.3249 | 1020.558 | 23 | 2 | 1 | y7 | ||
| 567.3249 | 1133.642 | 23 | 2 | 1 | y8 | ||
|
| |||||||
| SQDWAYAASK[Ubiquitin]E | Lys48 | 457.2055 | 619.304 | 23 | 3 | 1 | y5 |
| 457.2055 | 782.3673 | 23 | 3 | 1 | y6 | ||
| 457.2055 | 853.4044 | 23 | 3 | 1 | y7 | ||
| 457.2055 | 1039.484 | 23 | 3 | 1 | y8 | ||
| 685.3046 | 782.3673 | 26 | 2 | 1 | y6 | ||
| 685.3046 | 853.4044 | 26 | 2 | 1 | y7 | ||
| 685.3046 | 1039.484 | 26 | 2 | 1 | y8 | ||
| 685.3046 | 1154.511 | 26 | 2 | 1 | y9 | ||
|
| |||||||
| YLEK[Ubiquitin]PM[Oxid]EIAR | Lys97 | 460.5711 | 488.2822 | 24 | 3 | 1 | y4 |
| 460.5711 | 635.3176 | 24 | 3 | 1 | y5 | ||
| 460.5711 | 732.3704 | 24 | 3 | 1 | y6 | ||
| 460.5711 | 974.5082 | 24 | 3 | 1 | y7 | ||
| 460.5711 | 1103.551 | 24 | 3 | 1 | y8 | ||
| 460.5711 | 1216.635 | 24 | 3 | 1 | y9 | ||
| 690.353 | 732.3704 | 27 | 2 | 1 | y6 | ||
| 690.353 | 974.5082 | 27 | 2 | 1 | y7 | ||
| 690.353 | 1103.551 | 27 | 2 | 1 | y8 | ||
| 690.353 | 1216.635 | 27 | 2 | 1 | y9 | ||
|
| |||||||
| YLEK[Ubiquitin]PMEIAR | Lys97 | 455.2395 | 488.2822 | 23 | 3 | 1 | y4 |
| 455.2395 | 619.3226 | 23 | 3 | 1 | y5 | ||
| 455.2395 | 716.3754 | 23 | 3 | 1 | y6 | ||
| 455.2395 | 958.5133 | 23 | 3 | 1 | y7 | ||
| 455.2395 | 1087.556 | 23 | 3 | 1 | y8 | ||
| 455.2395 | 1200.64 | 23 | 3 | 1 | y9 | ||
| 682.3555 | 716.3754 | 26 | 2 | 1 | y6 | ||
| 682.3555 | 958.5133 | 26 | 2 | 1 | y7 | ||
| 682.3555 | 1087.556 | 26 | 2 | 1 | y8 | ||
| 682.3555 | 1200.64 | 26 | 2 | 1 | y9 | ||
Abbreviations: Q, quadrupole; m/z, mass to charge ratio; CE, collision energy; Z, charge state.