TABLE 4.
Oligosaccharide occupancy levels observed on non-consensus Asn and Gln residues before and after lectin enrichment
The pre-treatment level of NCG is inferred from the fold-enrichment of the glycosylated CH1 peptide due to lectin affinity chromatography. Reduction of occupancy levels was observed after treatment of the sample with PNGase F either prior to or after denaturation at elevated temperatures in the presence of 4 m guanidine HCl followed by reduction and alkylation as shown in the 4th and 5th columns, respectively.
| Glycan site | % Gly |
|||
|---|---|---|---|---|
| Unenriched | Enriched | Enriched de-Gly-R/Aa | Enriched R/A-de-Gly | |
| HC Asn-162 | 1.07 | 24.50 | 24.35 | 2.94 |
| HC Asn-360 | 0.12b | 2.73 | 2.58 | 0.03 |
| LC Asn-35 | 0.01b | 0.23 | 0.14 | NDc |
| LC Asn-164 | 0.02b | 0.44 | 0.38 | ND |
| LC Gln-106 | 0.02b | 0.59 | 0.47 | ND |
a R/A, reduced and alkylated.
b Value extrapolated from HC Asn-162 fold-enrichment.
c ND, not deteted.