FIGURE 2.

MS/MS verification of Halorubrum sp. PV6 S-layer glycoprotein Asn-94 glycosylation. To verify that glycosylation of the hexose-modified S-layer glycoprotein-derived peptide, ⁷⁸TGSYAIGGPDAADGAFNVTVVTPR¹⁰¹, occurs on Asn-94, the MS spectrum of the [M+2H]²⁺ base peak of this peptide, observed at m/z 1249.61, was obtained via mass-dependent acquisition. The y-ion series includes fragments that contain the hexose-modified Asn-94 residue. The inset shows the fragmentation scheme, with the Asn94-bound hexose being represented by the open circle. Peaks corresponding to y-ion series fragments are indicated by stars.