Fig 3.
N-glycosylation of S. acidocaldarius SlaB. A. LC-ESI MS analysis of a tryptic fragment of SlaB that includes Asn-278 revealed the peptide (inset) and its modification by a hexasaccharide comprising N-acetylhexosamine2-hexose3-sulfated quinovose. [M+2H]2+ ion peaks are presented. B. MS/MS profile of the [M+2H]2+ base peak of the peptide observed at m/z 1621.72. The inset schematically represents the fragmentation scheme. The N represents Asn-278, diamonds represent N-acetylhexosamines, full circles represent hexoses, open circles represent quinovose and S represents sulfation. The arrows indicating x10 reflect magnification of the ion peaks in the corresponding region of the m/z values on the graph.