Table 3.
Glycosylation sites and amino acid sequences of complex-type glycopeptides observed in LC-MS/MS analysis of a chymotryptic digest of reduced and alkylated E2.
| Sitea | Chymotryptic peptide | Glycopeptide mass | Glycan typec | Relative abundanced | ||
|---|---|---|---|---|---|---|
| Theoretical | Observed | Mass accuracy
(ppm) |
||||
|
N41
(N423) |
39HINSTAL45 | 1849.794 | 1849.786 | 4 | Man3-GlcNAc | 0.28 |
| 1995.852 | 1995.831 | 10 | Man3-GlcNAc-Fuc | 1 | ||
| 2132.873 | 2132.860 | 6 | Man 6 | 0.80 | ||
| 1970.820 | 1970.811 | 4 | Man 5 | 0.88 | ||
| 1808.767 | 1808.769 | 1 | Man 4 | 0.20 | ||
| 1646.714 | 1647.711 | 2 | Man 3 | 0.10 | ||
|
N48
(N430) |
48NESLNTGWLAG58b | 2198.921 | 2198.902 | 8 | Man3-Fuc | 0.18 |
| 2402.001 | 2401.984 | 7 | Man3-GlcNAc-Fuc | 1 | ||
| 2605.080 | 2605.071 | 4 | Man3-GlcNAc2-Fuc | 0.29 | ||
The numbers in parenthesis represent the positions of the N glycosylation sites which correspond to the positions in the HCV polyprotein of reference strain H (GenBank access number AF009606).
Anomalous chymotryptic cleavage sites.
The notation ManX indicates that X mannose residues are attached to the chitobiose core of each N-linked high mannose glycan. The rest of the notations indicate complex type glycans.
The relative abundance was determined from the deconvoluted mass spectrum over the mass range containing the glycopeptide ions corresponding to glycopeptides with the same amino acid sequence.