... N-Glycan structures of squid rhodopsin Existence of the a1 –3 and a1 –6 difucosylated innermost GlcNAc residue in a molluscan glycoprotein Noriko Takahashi1, Katsuyoshi Masuda2, Kenji Hiraki2, ... two potential glycosylation sites, Asn2 and Asn15,predominantly express the structure Mana1–6 (GlcNAc b1–2Mana1–3)Manb1–4GlcNAcb1– 4GlcNAc. In the case of bovine, human and frog rhodopsin, both of ... reducing end GlcNAc. Whensubjected to linkage analysis, glycan B1 gave terminal Fuc,terminal Man, terminal Gal, 3,6-linked Man, 4-linked GlcNAc and, importantly, a peak that can be assigned as4-linked...