Table 1.
Summary of O-GlcNAc-Containing Peptides Identified Using HCD-Triggered UVPD for Analysis of Tryptic Digests of O-GlcNAc-Modified TAB1 and Ph Proteins
| protein | glycopeptide | charge state (+) | Detected ion (m/z) | peptide mass (Da) | Mass error (ppm) | PEP2Db | Delta Mod score | Sequence coverage | Modified resc/known site |
|---|---|---|---|---|---|---|---|---|---|
| TAB1 | VYPVSVPYSa(g1)SAQSTSK | 2 | 951.97 | 1902.93 | 1.2 | 1.5e-13 | 766 | 93% | S395/Y41 |
| TAB1 | VYPVSVPYSS(g2)AQSTSK | 2 | 951.97 | 1902.93 | 1.3 | 6.1e-13 | 771 | 100% | S396/Y13 |
| TAB1 | VYPVSVPYSSAQS(g3)TSK | 2 | 951.97 | 1902.93 | 0.3 | 1.5e-12 | 761 | 100% | S399/N |
| TAB1 | VYPVSVPYSSAQSTS(g4)K | 2 | 951.97 | 1902.93 | 1.1 | 1.5e-12 | 659 | 100% | S401/N |
| TAB1 | TSVTLSLVMPSQGQMVNGAHS(g5)ASTLDEATPTLTNQSPTLTLQSTNTHTQSSSSSSDGGLFR | 4 | 1617.77 | 6467.07 | −0.8 | 1.4e-13 | 1120 | 92% | S423/N |
| TAB1 | TSVTLSLVMPSQGQMVNGAHSASTLDEATPTLTNQSPTLTLQSTNTHT(g6)QSSSSSSDGGLFR | 4 | 1617.77 | 6467.07 | −1.1 | 8.2e-15 | 1035 | 73% | T450/N |
| TAB1 | LWSVDHGEQSVVT(g7)AP | 2 | 914.44 | 1826.87 | −0.2 | 3.9e-9 | 697 | 100% | T502/N |
| ph1397–1589 | LSESFPILGASTEVPPMS(g2)LPVQAAISAPSPLAMPLGSPLSVALPTLAPLSVVTSGAAPK | 5 | 118.24 | 5937.19 | −0.7 | 7.2e-11 | 345 | 91% | S1457/N |
| ph1397–1589 | LSESFPILGASTEVPPMSLPVQAAIS(g3)APSPLAMPLGSPLSVALPTLAPLSVVTSGAAPK | 5 | 1188.24 | 5937.19 | 1.5 | 7.2e-16 | 537 | 95% | S1465/N |
| ph1397–1589 | SSEVNGTDRPPIS(g4)S WSVDDVSNFIR | 3 | 989.80 | 2967.40 | 1.6 | 1.3e-16 | 730 | 100% | S1511/N |
a
(g) denotes an identified O-GlcNAc modification site
b
Scoring criteria used for assessing the quality of PTM site localization based on a previously established two-dimensional target decoy strategy (PEP 2D scores < 10−5),42 and the Delta Mod metric yields a measure of site localization of each identified O-GlcNAc modification (Delta Mod scores > 40) using Byonic.
c
Modified amino acid position in the full-length protein.
d
Data are based on triplicate runs.