Figure 2.

Sequence, glycosylation, and peptide coverage of the green opsin construct by MS. Only peptides with a significant score with a p value of <0.05 were selected and further analyzed in triplicate. (A) Glycosylation sites are colored orange. The extracellular side of the receptor is colored green; the cytosolic domain is colored red, and the transmembrane domains are colored blue. Black lines indicate the peptide coverage in H₂O and D₂O, in both dark and bleached states. In the case of overlapping peptides, the percentage of H/D exchange applied is shown with a solid line. For gaps in the coverage, the missing percentage was derived from peptides with a dashed line. The green line indicates coverage only in the D₂O dark state, and the violet line displays peptide coverage found only in the D₂O bleached state. (B) MS/MS spectrum of the N-terminal peptide, residues 29–45. Residues N32 and N34 were detected as D32 and D34, respectively. The sequence is displayed above the spectrum, and the two glycosylated residues are colored orange. The b and y ions are colored red and blue, respectively. The M notation refers to the molecular ion.