Structural analysis of the oligosaccharides derived from glycodelin, a human glycoprotein with potent immunosuppressive and contraceptive activities

J Biol Chem. 1995 Oct 13;270(41):24116-26. doi: 10.1074/jbc.270.41.24116.


Glycodelin, also known as placental protein 14 (PP14) or progesterone-associated endometrial protein (PAEP), is a human glycoprotein with potent immunosuppressive and contraceptive activities. In this paper we report the first characterization of glycodelin-derived oligosaccharides. Using strategies based upon fast atom bombardment and electrospray mass spectrometry we have established that glycodelin is glycosylated at Asn-28 and Asn-63. The Asn-28 site carries high mannose, hybrid and complex-type structures, whereas the second site is exclusively occupied by complex-type glycans. The major non-reducing epitopes in the complex-type glycans are: Gal beta 1-4GlcNAc (lacNAc), GalNAc beta 1-4GlcNAc (lacdiNAc), NeuAc alpha 2-6Gal beta 1-4GlcNAc (sialylated lacNAc), NeuAc alpha 2-6Gal beta 1-4GlcNAc (sialylated lacdiNAc), Gal beta 1-4(Fuc alpha 1-3)GlcNAc (Lewisx), and GalNAc beta 1-4(Fuc alpha 1-3)GlcNAc (lacdiNAc analogue of Lewisx). It is possible that the oligosaccharides bearing sialylated lacNAc or lacdiNAc antennae may manifest immunosuppressive effects by specifically blocking adhesive and activation-related events mediated by CD22, the human B cell associated receptor. Oligosaccharides with fucosylated lacdiNAc antennae have previously been shown to potently block selectin-mediated adhesions and may perform the same function in glycodelin. The potent inhibitory effect of glycodelin on initial human sperm-zona pellucida binding is consistent with our previous suggestion that this cell adhesion event requires a selectin-like adhesion process. This result also raises the possibility that a convergence between immune and gamete recognition processes may have occurred in the types of carbohydrate ligands recognized in the human.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Contraceptive Agents*
  • Cyanogen Bromide
  • Epitopes / analysis
  • Epitopes / chemistry
  • Gas Chromatography-Mass Spectrometry
  • Glycodelin
  • Glycoproteins*
  • Humans
  • Immunosuppressive Agents*
  • Molecular Sequence Data
  • Oligosaccharides / chemistry*
  • Oligosaccharides / isolation & purification
  • Peptide Fragments / chemistry
  • Pregnancy Proteins / chemistry*
  • Spectrometry, Mass, Fast Atom Bombardment


  • Contraceptive Agents
  • Epitopes
  • Glycodelin
  • Glycoproteins
  • Immunosuppressive Agents
  • Oligosaccharides
  • PAEP protein, human
  • Peptide Fragments
  • Pregnancy Proteins
  • Cyanogen Bromide