Table 2.
Glycosylation sites and amino acid sequences of high mannose 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) |
||||
|
N35
(N417) |
32INTNGSW38 | 1682.678 | 1682.676 | 1 | Man 3 | 0.5 |
| 1844.731 | 1845.732 | 1 | Man 4 | 0.95 | ||
| 2006.784 | 2006.774 | 4 | Man 5 | 0.82 | ||
| 2168.837 | 2168.816 | 9 | Man 6 | 1 | ||
| 2330.889 | 2330.873 | 7 | Man 7 | 0.37 | ||
| 2492.942 | 2492.954 | 5 | Man 8 | 0.25 | ||
| 2654.995 | 2655.016 | 8 | Man 9 | 0.25 | ||
|
N66
(N448) |
66NSSGCPERL74 | 2015.799 | 2015.830 | 15 | Man 4 | 0.85 |
| 2177.852 | 2177.829 | 10 | Man 5 | 0.5 | ||
| 2339.905 | 2339.921 | 7 | Man 6 | 1 | ||
| 2501.957 | 2501.953 | 2 | Man 7 | 0.37 | ||
| 2664.010 | 2664.007 | 1 | Man 8 | 0.36 | ||
| 2826.063 | 2826.069 | 2 | Man 9 | 0.12 | ||
|
N94
(N476) |
88GPISYANGSGLDERPYCW105b | 3743.481 | 3743.457 | 6 | Man 8 | 0.17 |
| 3905.534 | 3905.519 | 4 | Man 9 | 0.50 | ||
| 4067.587 | 4067.628 | 10 | Hex1Man 9 | 1 | ||
| 4229.640 | 4229.704 | 15 | Hex2Man 9 | 0.25 | ||
| 4391.692 | 4391.766 | 17 | Hex3Man 9 | 0.22 | ||
| 0.18 | ||||||
|
N150
(N532) |
148GANDTDVFVL157 | 2428.137 | 2428.156 | 8 | Man 6 | 1 |
| 2590.031 | 2590.055 | 9 | Man 7 | 0.45 | ||
| 2752.084 | 2752.131 | 17 | Man 8 | 0.85 | ||
| 2914.137 | 2914.143 | 2 | Man 9 | 0.42 | ||
| 3076.190 | 3076.207 | 6 | Hex1Man 9 | 0.54 | ||
| 3238.243 | 3238.293 | 15 | Hex2Man 9 | 0.52 | ||
|
N158
(N540) |
156VLNNTRPPLGNWF168 | 2743.222 | 2743.241 | 7 | Man 5 | 0.39 |
| 2905.275 | 2905.262 | 4 | Man 6 | 1 | ||
| 3067.327 | 3067.361 | 11 | Man 7 | 0.15 | ||
| 3229.380 | 3229.405 | 8 | Man 8 | 0.10 | ||
| 3391.433 | 3391.451 | 5 | Man 9 | 0.07 | ||
|
N174
(N556) |
173MNSTGF178 | 1547.581 | 1547.580 | 1 | Man3 | 0.1 |
| 1709.634 | 1709.645 | 6 | Man4 | 0.4 | ||
| 1871.687 | 1871.690 | 2 | Man 5 | 0.62 | ||
| 2033.740 | 2033.732 | 4 | Man 6 | 1 | ||
| 2195.792 | 2195.799 | 3 | Man 7 | 0.30 | ||
| 2357.845 | 2357.844 | 1 | Man 8 | 0.31 | ||
| 2519.898 | 2519.901 | 1 | Man 9 | 0.27 | ||
|
N241
(N623) |
235HYPCTINY242 | 2225.855 | 2225.835 | 9 | Man 5 | 0.09 |
| 2387.908 | 2387.883 | 10 | Man 6 | 1 | ||
| 2549.950 | 2549.960 | 4 | Man 7 | 0.28 | ||
| 2712.013 | 2711.960 | 20 | Man 8 | 0.19 | ||
| 2874.066 | 2874.069 | 1 | Man 9 | 0.13 | ||
|
N263
(N645) |
251VGGVEHRLEAACNW264 | 2756.148 | 2756.120 | 10 | Man5 | 0.1 |
| 2918.201 | 2918.175 | 9 | Man 6 | 1 | ||
| 3080.253 | 3080.230 | 7 | Man 7 | 0.31 | ||
| 3242.306 | 3242.282 | 7 | Man 8 | 0.33 | ||
| 3404.359 | 3404.325 | 10 | Man 9 | 0.5 | ||
a
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).
b
Represents a carboxymethylated cysteine residue.
c
The notation ManX indicates that X mannose residues are attached to the chitobiose core of each N-linked high mannose glycan.
d
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.