Table I. Detected modifications for the ISB standard protein mix data set.
|
Mono-modifications | |||||
|---|---|---|---|---|---|
| Δm (Da) | Δt (min) | d-score | Pairs (PEP) | Interpretation | Mass deviation (Da) |
| 37.94689 | 0.020 | 1127.2 | 2,023 (0.02) | Calcium adduct | −0.00005 |
| 21.98167 | 0.020 | 472.2 | 1,358 (0.02) | Sodium adduct | −0.00027 |
| 113.08411 | −0.012 | 151.2 | 48 (0.02) | I/L (amino acid) | 0.00005 |
| 0.98433 | 0.800 | 73.6 | 335 (0.02) | Deamidation | 0.00031 |
| 151.99699 | 1.842 | 34.2 | 125 (0.05) | Carbamidomethyl DTT | 0.00042 |
| 156.09987 | −2.389 | 30.8 | 119 (0.05) | R (amino acid) | −0.00124 |
| 128.09461 | −2.915 | 29.9 | 144 (0.05) | K (amino acid) | −0.00035 |
| 170.10512 | −0.014 | 29.3 | 39 (0.05) | GI/L or AV (amino acids) | −0.00040 |
| 104.09558 | −13.108 | 20.2 | 6 (0.02) | False positive | |
| 15.99421 | −4.101 | 17.3 | 62 (0.05) | Oxidation | −0.00071 |
| 99.06819 | 0.671 | 15.0 | 43 (0.10) | V (amino acid) | −0.00022 |
| 18.00828 | −0.255 | 13.6 | 36 (0.10) | Dehydration/N-term pyro-glutamic acid | −0.00229 |
| 26.01532 | 2.581 | 10.5 | 67 (0.10) | Acetaldehyde(+26) | −0.00033 |
|
Additive pseudo-modifications | |||||
|---|---|---|---|---|---|
| Δm (Da) | Δt (min) | d-score | Pairs (PEP) | Interpretation | Mass deviation (Da) |
| 43.96545 | 0.0717 | 207.2 | 194 (0.02) | Double sodium | 0.00156 |
| 75.89452 | 0.0340 | 175.4 | 185 (0.02) | Double calcium | 0.00063 |
| 59.93015 | 0.0206 | 169.1 | 278 (0.02) | Calcium + sodium | 0.00127 |
| 38.93119 | 0.8715 | 26.7 | 53 (0.05) | Calcium + deamidation | 0.00023 |
| 189.94359 | 1.3348 | 20.8 | 20 (0.05) | Calcium + carbamidomethyl DTT | 0.00008 |
| 22.96927 | 0.4303 | 18.2 | 3 (0.05) | Sodium + deamidation | 0.00331 |
|
Subtractive pseudo-modifications | |||||
|---|---|---|---|---|---|
| Δm (Da) | Δt (min) | d-score | Pairs (PEP) | Interpretation | Mass deviation (Da) |
| 15.96596 | 0.0011 | 483.7 | 792 (0.02) | Calcium − sodium | 0.00096 |
| 6.01759 | 0.0217 | 232.8 | 165 (0.02) | Double sodium − calcium | 0.00064 |
| 53.91554 | 0.0444 | 111.1 | 116 (0.02) | Double calcium − sodium | 0.00360 |
| 31.93087 | 0.0031 | 110.0 | 41 (0.02) | Double calcium − double sodium | 0.00088 |
| 36.96257 | −0.7860 | 47.3 | 34 (0.02) | Calcium − deamidation | −0.00035 |
| 20.99921 | −0.8399 | 27.7 | 73 (0.05) | Sodium − deamidation | 0.00187 |
| 118.15417 | −2.4277 | 25.7 | 70 (0.05) | R − calcium | 0.00000 |
| 114.05048 | 2.3156 | 19.8 | 2 (0.05) | Carbamidomethyl DTT − calcium | 0.00085 |
| 90.14823 | −2.8493 | 18.7 | 42 (0.05) | K − calcium | 0.00021 |
| 15.00951 | −5.0909 | 16.7 | 28 (0.10) | Oxidation − deamidation | −0.00107 |
| 140.10718 | 1.4453 | 14.5 | 26 (0.10) | R − oxidation | 0.00098 |
| 16.94414 | 0.9930 | 11.1 | 24 (0.10) | Calcium + deamidation − sodium | −0.00514 |
| 21.95289 | 4.2442 | 10.5 | 98 (0.10) | Calcium − oxidation | 0.00087 |