Biochemical characterization of hamster oviductin as a sulphated zona pellucida-binding glycoprotein.

摘要: Oviductins are a family of glycoproteins, synthesized and released by oviductal secretory cells, which bind to the zona pellucida oocyte after ovulation. Hamster oviductin migrates as diffuse species 160-350 kDa during SDS/PAGE under reducing well non-reducing conditions. In this report, we describe one-step purification hamster using either immuno- or lectin-affinity chromatography. Probing with specific lectins showed that glycoprotein contains terminal alpha-D-GalNAc, alpha-D-NeuAc non-terminal beta-D-(GlcNAc)2 residues, but fails react concanavalin A Ulex Europeus A-1 for branched alpha-D-mannose alpha-L-fucose moieties respectively. Intraovarian oocytes do not contain demonstrate here immunoaffinity-purified readily binds their zonae pellucidae in vitro, thus mimicking vivo phenomenon. Two major immunologically related forms (named alpha beta) were characterized one- two-dimensional gel electrophoresis. The alpha-form (160-210 kDa) has an acidic pI 3.5-4.5 beta-form (approx. 210-350 is localized at cathodic site isoelectric focusing dimension; between these two lies smear minor-charge isomers. Peptide mapping both papain Staphylococcus aureus V8 protease yielded fragments identical size. Moreover, share same N-terminal sequence display no significant homology other reported proteins. Treatment trifluoromethanesulphonic acid protein size can be generated from beta-form. Both alpha- beta-forms sulphated on O-linked oligosaccharide side chains phosphorylated. Collectively, results suggest polymorphism observed PAGE consequence different glycosylation patterns polypeptide chain itself. mostly O-glycosylated few N-linked 10 kDa). We propose mucin-type might act protective secretion influencing first steps reproductive process necessary normal triggering fertilization early embryonic development.