title: N-Glycosylation profiling of turtle egg yolk: expression of galabiose structure.
abstract: To understand the roles of species-specific carbohydrates, systematic studies of interspecific glycan analyses are imperative. An extensive series of glycomics studies on approximately 180 kinds of bird eggs have demonstrated that 60-70% of the birds, which are closely related in phylogeny, express the alpha-Galp-(1-->4)-Galp structure on their egg glycoproteins. This prompted us to investigate the glycosylation profiles of eggs from an evolutionarily related organism, a sea turtle (reptilian). We performed N-glycosylation profiling of turtle egg yolk by using HPLC mapping in conjunction with mass spectrometric methods and thereby demonstrated that the alpha-Galp-(1-->4)-Galp groups are displayed on approximately 38% of total N-glycans. Our findings suggest that the ability to express the galabiose structure was acquired at an early stage of diversification in amniotes.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Yagi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Shin-Yi
authors.initials: SY
authors.lastname: Yu
authors.forename: Noriko
authors.initials: N
authors.lastname: Takahashi
authors.forename: Kay-Hooi
authors.initials: KH
authors.lastname: Khoo
authors.forename: Yuan Chuan
authors.initials: YC
authors.lastname: Lee
authors.forename: Koichi
authors.initials: K
authors.lastname: Kato
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D004187:Disaccharides / Q000032:analysis* / Q000096:biosynthesis; D004530:Egg Yolk / Q000737:chemistry*; D054794:Glycomics / Q000379:methods*; D006031:Glycosylation; D008969:Molecular Sequence Data; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014426:Turtles / Q000378:metabolism*
chemical_list: D004187:Disaccharides; C032103:4-O-alpha-D-galactopyranosyl-D-galactose