Table II. List of identified glycopeptides and corresponding glycoforms for the N- and O-linked oligosaccharides from the RNase B and fetuin tryptic digest.
| Protein name | Sequence of identified peptides | Oligosacchride composition | Glycosylation site | Glycopeptide mass |
||
|---|---|---|---|---|---|---|
| Calculated | Measured | |||||
| aa | RNase B | (R)NLTK(D) | GlcNAc2 Man5 | Asn-60 | 1690.70 | 1690.70 |
| b | ″ | ″ | GlcNAc2 Man6 | ″ | 1852.76 | 1852.78 |
| c | ″ | ″ | GlcNAc2 Man7 | ″ | 2014.81 | 2014.82 |
| d | ″ | ″ | GlcNAc2 Man8 | ″ | 2176.86 | 2176.86 |
| e | ″ | ″ | Glc2 NAc2 Man9 | ″ | 2338.91 | 2338.92 |
| f | Bovine fetuin | (K)KLCam CPDCam CPLLAPLNDSR(V) | Hex6 HexNAc5 SA3 | Asn-138 | 4728.93 | 4728.93 |
| g | ″ | ″ | Hex5 HexNAc4 SA2 | ″ | 4072.70 | 4072.68 |
| h | ″ | ″ | Hex6 HexNAc5 SA4 | ″ | 5020.02 | 5019.96 |
| i | ″ | (K)LCamCPDCam CPLLAPLNDSR(V) | Hex5 HexNAc4 SA2 | ″ | 3944.61 | 3944.58 |
| j | ″ | ″ | Hex6 HexNAc5 SA3 | ″ | 4600.84 | 4600.80 |
| k | ″ | ″ | Hex6 HexNAc5 SA4 | ″ | 4891.93 | 4891.89 |
| l | ″ | (R)RPTGEVYDIEIDTLETTCam CHVLDPTPLA NCamCSVR(Q) | Hex5 HexNAc4 SA2 | Asn-81 | 5875.54 | 5875.40 |
| m | ″ | ″ | Hex6 HexNAc5 SA3 | ″ | 6531.77 | 6531.68 |
| n | ″ | ″ | Hex6 HexNAc5 SA4 | ″ | 6822.86 | 6822.88 |
| o | ″ | (R)VVHAVEVALATFNAESNGSYLQLVEISR(A) | Hex6 HexNAc5 SA3 | Asn-158 | 5876.57 | 5876.56 |
| p | ″ | ″ | Hex6 HexNAc5 SA4 | ″ | 6167.66 | 6167.56 |
| q | ″ | ″ | Hex6 HexNAc5 SA5 | ″ | 6458.75 | 6458.65 |
| r | ″ | (R)VTCam CTLFQTQPVIPQPQPDGAEAEAPSAVPDAAGPTTPSAAGPPVASVVVGPSVVAVPLPLHR(A) | Hex2 HexNAc2 SA2 | T228–288 | 7326.60 | 7326.40 |
| s | ″ | ″ | Hex2 HexNAc2 SA3 | ″ | 7617.70 | 7617.70 |
| t | ″ | ″ | Hex3 HexNAc3 SA3 | ″ | 7982.81 | 7982.64 |
| u | ″ | ″ | Hex3 HexNAc3 SA4 | ″ | 8273.91 | 8273.79 |
| v | ″ | ″ | Hex4 HexNAc4 SA4 | ″ | 8639.04 | 8639.16 |
| w | ″ | ″ | Hex4 HexNAc4 SA5 | ″ | 8930.13 | 8930.43 |
a The 23 glycopeptides detected by IP-NPLC-MS of ∼300 fmol of the RNase B and fetuin tryptic digest have been assigned a letter code (a–w) in order to facilitate identification. The consensus sequence of N-glycosylation and possible O-glycosylation sites are highlighted (12, 13). CamC, carboxyamidomethylcysteine.