Glycoconjugate Journal

, Volume 2, Issue 3, pp 209–228

Structures of the carbohydrate units of polysialoglycoproteins isolated from the eggs of four species of salmonid fishes

  • Mariko Iwasaki
  • Sadako Inoue

DOI: 10.1007/BF01049269

Cite this article as:
Iwasaki, M. & Inoue, S. Glycoconjugate J (1985) 2: 209. doi:10.1007/BF01049269


Fish egg polysialoglycoprotein (PSGP) is a novel type of 200 kDa-glycoprotein containing more than 50% sialic acid by weight and about 90O-glycosidically-linked sialoglycan units per molecule. Of about 100 different molecular species assumed to be present in a sialoglycan mixture obtained by alkaline borohydride treatment ofSalvelinus leucomaenis pluvius PSGP, 23 mono- to tetrasialylglycans were isolated by anion-exchange chromatography and preparative column chromatography on porous silica, and their structures were determined. Core asialo-oligosaccharides were obtained from PSGP of four species of salmonid fishes by exhaustive enzymatic desialylation of sialoglycan mixtures and the structures of purified compounds were determined. Two complete types of asialopentasaccharide core structures, Fucα1-3GalNAcβ1-3Galβ1-4 Galβ1-3GalNAcOL, and GalNAcβ1-4GalNAcβ1-3Galβ1-4Galβ1-3GalNAcOL, and all of the possible biosynthetic precursors of these pentasaccharide cores were found in every PSGP examined. All types of oligosaccharide chains, both complete and incomplete, were found to occur in highly sialylated forms in PSGP.

Key words

polysialoglycoproteinoligosialyl O-linked glycansoligosaccharide fractionation



N-acetylneuraminic acid


N-glycolylneuraminic acid






sialidase-resistant oligosaccharide

Copyright information

© Glycoconjugate Journal 1985

Authors and Affiliations

  • Mariko Iwasaki
    • 1
  • Sadako Inoue
    • 1
  1. 1.School of Pharmaceutical SciencesShowa UniversityTokyoJapan