A precise structural analysis of a fertilization-associated carbohydrate-rich glycopeptide isolated from the fertilized eggs of euryhaline killi fish (Fundulus heteroclitus). Novel penta-antennary N-glycan chains with a bisecting N-acetylglucosaminyl residue.
A novel carbohydrate-rich sialoglycopeptide of apparent molecular mass approximately 6 kDa was isolated from the fertilized eggs of Fundulus heteroclitus (euryhaline killi fish). This glycopeptide is a member of the L-hyosophorin family, characterized by its high content of carbohydrate (80-90% by weight) and formed by depolymerization of the precursor glycopoly-protein (H-hyosophorin) upon fertilization. The structures of the N-glycan chains were unambiguously established by a combination of compositional analysis, methylation analysis, selective chemical degradation (periodate oxidation-Smith degradation and hydrazinolysis-nitrous acid deamination), enzymatic (peptide:N-glycosidase F, several beta-galactosidases, beta-hexosaminidase and alpha-galactosidase) digestions and instrumental analyses (1H-NMR and fast atom bombardment mass spectrometry) to have the novel and unique carbohydrate sequences, Gal alpha 1-->3(Gal beta 1-->4)Gal beta 1-->4GlcNAc beta 1--> and Gal alpha 1-->3(+/- GalNAc beta 1-->4GlcNAc beta 1-->3Gal beta 1-->4)Gal beta 1-->4GlcNAc beta 1-->. This study represents the first detailed investigation of the nature of bulky complex asparagine-linked penta-antennary glycans with a bisecting GlcNAc residue in glycoproteins. Expression of such bulky multiantennary glycan units on proteins may be essential during early embryogenesis.
Taguchi
T
T
Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Japan.
Kitajima
K
K
Muto
Y
Y
Inoue
S
S
Khoo
K H
KH
Morris
H R
HR
Dell
A
A
Wallace
R A
RA
Selman
K
K
Inoue
Y
Y
D000117:Acetylglucosamine / Q000737:chemistry*; D000818:Animals; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis*; D005306:Fertilization; D029941:Fish Proteins; D006023:Glycoproteins / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000737:chemistry; D006834:Hydrazines / Q000737:chemistry; D007695:Killifishes; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D009608:Nitrous Acid / Q000737:chemistry; D010063:Ovum / Q000737:chemistry*; D010504:Periodic Acid / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D011522:Protons; D016339:Spectrometry, Mass, Fast Atom Bombardment
D002241:Carbohydrates; D029941:Fish Proteins; D006023:Glycoproteins; D006834:Hydrazines; D011134:Polysaccharides; D011522:Protons; D010504:Periodic Acid; C061150:hyosophorin protein, Fish; C029424:hydrazine; D006026:Glycoside Hydrolases; D009608:Nitrous Acid; D000117:Acetylglucosamine