Isolation and characterization of CD47 glycoprotein: a multispanning membrane protein which is the same as integrin-associated protein (IAP) and the ovarian tumour marker OA3

Biochem J. 1994 Dec 1;304 ( Pt 2)(Pt 2):525-30. doi: 10.1042/bj3040525.


The CD47 glycoprotein was isolated from human erythrocytes by immunoprecipitation using monoclonal antibody (mAb) BRIC-125. Enzymic deglycosylation of the protein showed it contained N-linked oligosaccharides, and trypsin proteolysis of the protein in situ in the erythrocyte membrane cleaved it into two portions, one of which was glycosylated. Both the intact protein and the glycosylated fragment had blocked N-termini. Amino acid sequence was obtained from several proteolytic fragments of CD47. Comparison with the sequence database showed the protein to be very similar to or identical with OA3, a multispanning membrane protein. The protein also appears to be the same as the integrin-associated protein, which has a role in cell adhesion in non-erythroid cells. CD47 has six potential N-glycosylation sites, five of which are in an Ig superfamily domain. We show that three of these sites carry N-glycans in erythrocytes. Immunocytochemical staining of human tissues showed that CD47 was broadly distributed on mesenchyme and epithelia at multiple sites. Reactivity was particularly prominent in surface and ductular epithelia, and in the brain. The possible roles of the CD47 glycoprotein are discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies, Monoclonal
  • Antigens, CD / blood*
  • Antigens, CD / chemistry
  • Brain Chemistry
  • CD47 Antigen
  • Carbohydrate Conformation
  • Carrier Proteins / blood*
  • Carrier Proteins / chemistry
  • Erythrocytes / chemistry*
  • Female
  • Glycosylation
  • Humans
  • Immunosorbent Techniques
  • Liver / chemistry
  • Membrane Proteins / blood*
  • Molecular Sequence Data
  • Oligosaccharides / analysis
  • Ovarian Neoplasms / chemistry
  • Peptide Fragments / chemistry
  • Peptide Fragments / metabolism
  • Sequence Homology
  • Tissue Distribution
  • Trypsin / metabolism


  • Antibodies, Monoclonal
  • Antigens, CD
  • CD47 Antigen
  • CD47 protein, human
  • Carrier Proteins
  • Membrane Proteins
  • Oligosaccharides
  • Peptide Fragments
  • Trypsin