Diverse lectin-binding specificity of four ZP3 glycoprotein isoforms with a discrete isoelectric point in chicken egg coat

Biochem Biophys Res Commun. 2012 Aug 3;424(3):586-92. doi: 10.1016/j.bbrc.2012.06.157. Epub 2012 Jul 7.

Abstract

The vertebrate egg coat corresponding to mammalian zona pellucida is a filamentous matrix composed of highly and heterogeneously glycosylated proteins designated ZP glycoproteins including ZP1 to 4, ZPD and ZPAX, and play important roles in species-specific egg-sperm interactions. Recent advance in structural biology of chicken ZP3 provided new insights into molecular mechanisms of the egg-coat function involving its carbohydrate moieties. In this study, chicken ZP3 was separated into four major and distinct isoforms with different pI in 2D-PAGE. To investigate the meanings of the ZP3 heterogeneity in egg-sperm interactions, we preliminary analyzed glycan diversity on the molecules by using lectin-staining assays. The four major ZP3 isoforms 4-7 (from acidic to basic) were recognized equally with PNA (Galβ1-3GalNAc), but the isoforms 5-7 were recognized dominantly with WGA ((β-GlcNAc)n, clustered Sia), PHA-E (bi- and triantennary N-glycan containing Galβ1-4GlcNAcβ1-2Manα1-6) and RCA I (terminal Galβ1-4GlcNAc), respectively. Despite such sugar chain diversity among the ZP3 isoforms, a partner in the egg coat, ZP1, showed specific binding to each isoform equally. Localization of ZP1 and ZP3 in the egg-coat matrix were also analyzed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Tumor-Associated, Carbohydrate / chemistry
  • Antigens, Tumor-Associated, Carbohydrate / metabolism
  • Chick Embryo
  • Egg Proteins / blood
  • Egg Proteins / chemistry
  • Egg Proteins / metabolism*
  • Fluorescent Antibody Technique
  • Isoelectric Point
  • Lectins / chemistry
  • Lectins / metabolism*
  • Membrane Glycoproteins / blood
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / metabolism*
  • Ovum / metabolism
  • Protein Isoforms / blood
  • Protein Isoforms / chemistry
  • Protein Isoforms / metabolism
  • Receptors, Cell Surface / blood
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / metabolism*
  • Sperm-Ovum Interactions
  • Zona Pellucida Glycoproteins

Substances

  • Antigens, Tumor-Associated, Carbohydrate
  • Egg Proteins
  • Lectins
  • Membrane Glycoproteins
  • Protein Isoforms
  • Receptors, Cell Surface
  • Zona Pellucida Glycoproteins
  • Thomsen-Friedenreich antigen