TABLE 1.
Analysis of the MS/MS spectrum of each of the modified tryptic peptides
| Sequence | Position | No. of hexoses | Fragment ions | Calculated m/z |
|---|---|---|---|---|
| PDNVSINAETAGR | Asn444 | 0, 1 | b3, y11 | 753.3575 |
| TTLTNTTLESILK | Asn484 | 1, 2 | y9, y9 | 798.9326 + 879.9590 |
| GTFVNITANQR | Asn497 | 1, 2 | y7, y7 | 691.8492 + 772.8756 |
| GANLTIYSGGWVDVHK | Asn546 | 1 | b3, y14 | 939.9652 |
| NISLGAQGNINITAK | Asn560, Asn570 | 1, 1 | b2, y5 | 919.4731 |
| FNNVSLNGTGSGLQFTTK | Asn605, Asn609 | 1, 1 | b3, y12 | 1105.029 |
| FNNVSLNGTGSGLQFTTK | Asn605, Asn609 | 1, 2 | (b4), y12 | 1186.0554 |
| FEGTLNISGK | Asn636 | 1, 2 | (b6), y5, y5 | 614.3080 + 695.3352 |
| VNISMVLPK | Asn642 | 1, 2 | b2, y8, y8 | 581.8230 + 662.8494 |
| YFNVSTGSSLR | Asn773 | 1, 2 | b3, y9, (b3), y9 | 696.8357 + 777.8621 |
| DTTFNVER | Asn709 | 1 | b5, y4 | 572.2619 |
| DLTLNATGGNITLLQVEGTDGMIGK | Asn801, Asn806 | 1, 1 | y16, y21 | 1428.2075 |
| DLTLNATGGNITLLQVEGTDGMIGK | Asn801, Asn806 | 1, 2 | y16 | 1590.2604 |
| KNITFEGGNITFGSR | Asn828, Asn835 | 1, 1 | b9, y14 | 982.976 |
| KNITFEGGNITFGSR | Asn828, Asn835 | 1, 2 | b9, y7, y14 | 1064.0024 |
| AITNFTFNVGGLFDNK | Asn912 | 1, 2 | (y14, b5), (b5, more b ions) | 960.4729 + 1041.4993 |
| GNSNISIAK | Asn928 | 1 | y6 | 533.2748 |
| NLSITTNSSSTYR | Asn952 | 1, 2 | b7, y7, b7, y7 | 803.3838 + 884.4102 |
| NLSITTNSSSTYR | Asn946, Asn952 | 1, 2 | b2, y7 | 965.44 |
| TIISGNITNK | Asn964 | 1, 2 | b6, y5, b6, y5 | 611.8299 + 692.8563 |
| NGDLNITNEGSDTEMQIGGDVSQK | Asn973 | 1 | b6 | 1342.5956 |
| EGNLTISSDK | Asn995 | 0, 1 | b3, y8 | 613.2933 |
| INITK | Asn1004 | 1 | b2, y4 | 375.7158 |
| AGVDGENSDSDATNNANLTIK | Asn1029 | 1, 2 | b17, y5, y5 | 1134.5091 + 1215.5355 |
| LTQDLNISGFNK | Asn1044 | 1, 2 | b6, y7, y7 | 756.3830 + 837.4094 |
| NVTVNNNITSHK | Asn1131 | 0, 1, 2 | y6, y6 | 751.8759 + 832.9023 |
| ITTKTGTTINATTGNVE | Asn1156 | 1, 2 | y8, b10, y8 | 942.4758 + 1023.5023 |
| AANVTLNTTGTLTTVK | Asn1348, Asn1352 | 1, 1 | (b3), b4, y142+, y152+, y10 | 964.9992 |
| GSNINATSGTLVINAK | Asn1366 | 2 | y12 | 942.4758 |
This table lists all peptides with identified modification sites. The modification sites are numbered according to the position of the modified amino acid in the intact protein sequence, beginning with the methionine in the signal peptide. The peptide marked in boldface lettering has a modification that is not part of the NX(S/T) consensus sequon. The underlined letters indicate modification sites, and the boldface letters indicate double modification sites. The table also lists the observed fragments ions that allow the localization of the modification