title: Sugar chains of serum transferrin from patients with carbohydrate deficient glycoprotein syndrome. Evidence of asparagine-N-linked oligosaccharide transfer deficiency.
abstract: The structure of over 93% of the sugar chains of serum transferrin purified from three patients with carbohydrate-deficient glycoprotein (CDG) syndrome was Neu5Ac alpha 2-->6Gal beta 1-->4GlcNAc beta 1-->2Man alpha 1-->6 (Neu5Ac alpha 2-->6Gal beta 1-->4GlcNAc beta 1-->2Man alpha 1-->3)Man beta 1-->4GlcNac beta 1-->4GlcNAc, similar to that in a healthy control. On chromatofocusing, CDG syndrome transferrin was separated into three major isoforms, S4, S2, and S0, containing 4, 2, and 0 sialic acids/molecule at pH 5.12 (5.16), 5.42, and 5.80, respectively. On 7.5% SDS-polyacrylamide gel electrophoresis, the molecular masses of transferrin isoforms S4, S2, and S0 were 80, 77, and 74 kDa, respectively. Transferrin isoforms S4 and S2 were linked to 2 and 1 mol of sialylated biantennary sugar chain/transferrin molecule, on the other hand, isoform S0 was not linked to any asparagine-N-linked oligosaccharide. Accordingly, CDG syndrome can be concluded to be an asparagine-N-linked oligosaccharide transfer deficiency, although the primary deficient enzyme has not yet been determined.
authors.affiliation: Department of Biochemistry, Sasaki Institute, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: H
authors.initials: H
authors.lastname: Ideo
authors.forename: T
authors.initials: T
authors.lastname: Ohkura
authors.forename: K
authors.initials: K
authors.lastname: Fukushima
authors.forename: I
authors.initials: I
authors.lastname: Yuasa
authors.forename: K
authors.initials: K
authors.lastname: Ohno
authors.forename: K
authors.initials: K
authors.lastname: Takeshita
mesh_terms: D001216:Asparagine / Q000378:metabolism*; D002239:Carbohydrate Metabolism, Inborn Errors / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002241:Carbohydrates; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007526:Isoelectric Point; D037102:Lectins; D008661:Metabolism, Inborn Errors / Q000097:blood*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000097:blood* / Q000737:chemistry; D013577:Syndrome; D014168:Transferrin / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D002241:Carbohydrates; D037102:Lectins; D009844:Oligosaccharides; D014168:Transferrin; D001216:Asparagine