Table 1.
Putative peptide or EGS-crosslinked peptides identified from complete trypsinolysis of EGS-crosslinked HbII.
| Mass/charge ratio (m/z) | Charge statea | Putative peptide species | |||||
| (Peptide assignment receiving best SearchXlinks score) | |||||||
| Peptide 1b | Polymer, Domainc | Peptide 2b | Polymer, Domainc | SXL Score | Noted | ||
| 626.462f | +2 | 715-FSSIGK-720 | TP, Domain 5 | 883-QLK-885 | TP or CP, Domain 6 | 11.5 | XLP |
| 648.457 | +2 | 738-EHIKR-742 | TP or CP, Domain 5 | 883-QLK-885 | TP or CP, Domain 6 | 6.0 | XLP |
| 927.400e,f | +1 | 931-GFK-933 | TP, Domain 6 | 931-GFK-933 | CP, Domain 6 | 21.0 | XLP |
| 983.462 | +1 | 1138-IFTKVFTK-1145 | TP, Domain 8 | - | - | 10.0 | UmP |
| 1273.996 | +1 | 68-NIPASELASSER-79 | TP, Domain 1 | - | - | 16.0 | UmP |
| 1405.492 | +1 | 672-VFAK-675 | TP or CP, Domain 5 | 742-RGLSRK-747 | TP or CP, Domain 5 | 11.5 | XLP |
| 1418.573e,f | +1 | 301-ASWNK-305 | TP or CP, Domain 2 | 29-ATIKR-33 | TP or CP, Domain 1 | 130.5 | XLP |
| 1542.509f | +1 | 1016-HAISVTTK-1023 | TP or CP, Domain 7 | 493-EAIK-496 | CP, Domain 4 | 153.0 | XLP |
| Mass/charge ratio (m/z) | Charge statea | Mass/charge Ratio Expected (m/z) | Total Possible Peptide Assignment | ||||
| 626.462f | +2 | 626.323 | 6 | ||||
| 648.457 | +2 | 648.348 | 7 | ||||
| 927.400e,f | +1 | 927.446 | 1 | ||||
| 983.462 | +1 | 983.593 | 5 | ||||
| 1273.996 | +1 | 1273.639 | 17 | ||||
| 1405.492 | +1 | 1405.780 | 20 | ||||
| 1418.573e,f | +1 | 1418.727 | 5 | ||||
| 1542.509f | +1 | 1541.806 | 38 | ||||
a Charge state of the peaks were inferred from the ESI-MS zoom scan data obtained. The inferred charged states were confirmed by consulting the PMF.
b Crosslinked lysines were in bold.
c TP, T polymer; CP, C polymer.
d XLP, EGS-crosslinked peptides; UmP, unmodified peptide.
e Statistical significances of b and y-type ion matchings were measured for these peaks (See also Table 2).
f Further identifications of peaks remaining unannotated after SearchXlinks scoring were done for these peaks, and afterwards a majority of significant peaks were identified. [See Additional file 1, 2, 3, 4]