Table I Identified HR O-glycopeptides of IgA1 (Ale) myeloma protein

A complete list of observed N- and C-terminal fragments, m/z values, and mass errors are provided in supplemental Table 1.

Glycan structure of identified Val222–Arg245 and Thr228–Arg245O-glycopeptidesRelative abundance ± S.D.a,b
%
(GalNAc)6Gal40.84 ± 0.13
(GalNAc)6Gal31.19 ± 0.11
(GalNAc)5Gal55.01 ± 0.92
(GalNAc)5Gal424.65 ± 4.18
(GalNAc)5Gal4(NeuAc)10.30 ± 0.14
(GalNAc)5Gal311.16 ± 1.26
(GalNAc)5Gal21.09 ± 0.27
(GalNAc)4Gal434.33 ± 0.80
(GalNAc)4Gal4(NeuAc)10.57 ± 0.21
(GalNAc)4Gal318.12 ± 2.82
(GalNAc)4Gal22.25 ± 0.91
(GalNAc)3Gal30.49 ± 0.41
  • a Relative abundance of each glycopeptides is expressed as a percentage against the sum of total ion current of glycopeptides detected with the same backbone amino acid sequence, determined similarly to the calculations of Rebecchi et al. (37).

  • b Relative abundance was calculated from four independent runs based on glycan profiles of Val222–Arg245 and Thr228–Arg245 glycopeptides. Our data showed that Thr225 is almost exclusively present with disaccharide (see supplemental Table 1 and supplemental Fig. 4A).