title: Synthesis of the carbohydrate moiety from the parasite Echinococcus multilocularis and their antigenicity against human sera.
abstract: Stereocontrolled syntheses of biotin-labeled oligosaccharide portions with a Galβ1-3GalNAc core of the Em2 glycoprotein antigen obtained from the parasite Echinococcus multilocularis have been accomplished. Trisaccharide Galβ1-3(GlcNAcβ1-6)GalNAcα1-R (G), tetrasaccharide Galβ1-3(Galβ1-4GlcNAcβ1-6)GalNAcα1-R (J) and pentasaccharide Galβ1-3(Galα1-4Galβ1-4GlcNAcβ1-6)GalNAcα1-R (K) (R=biotinylated probe) were synthesized by block synthesis by the use of 5-(methoxycarbonyl)pentyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl-(1→3)-2-azido-4-O-benzyl-2-deoxy-α-d-galactopyranoside as a common glycosyl acceptor. Moreover, linear trisaccharide Galα1-4Galβ1-3GalNAcα1-R (H) and branched tetrasaccharide Galα1-4Galβ1-3(GlcNAcβ1-6)GalNAcα1-R (I) were synthesized by stepwise condensation. We examined the antigenicity of these five oligosaccharides by an enzyme linked immunosorbent assay (ELISA). Our results demonstrate that biotinylated oligosaccharides H, I and K show good serodiagnostic potential to detect infections caused by the parasite E. multilocularis. Among them the linear sequence Galα1-4Galβ1-3GalNAcα1-R in oligosaccharide (H) appears to show the highest sensitivity (95%). Moreover, our study clarified the dominant carbohydrate epitope of Em2 antigen.
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Koizumi
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Yamano
authors.forename: Frank
authors.initials: F
authors.lastname: Schweizer
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Takeda
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Kiuchi
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Hada
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000097:blood / Q000737:chemistry; D002236:Carbohydrate Conformation; D048210:Echinococcus multilocularis / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D009844:Oligosaccharides / Q000097:blood* / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000947:Antigens, Helminth; D009844:Oligosaccharides