Isolation and characterization of 5T4, a tumour-associated antigen

Int J Cancer. 1990 Jan 15;45(1):179-84. doi: 10.1002/ijc.2910450132.


The monoclonal antibody (MAb) 5T4 defines a human trophoblast antigen marker with a restricted pattern of expression in normal adult tissues but this antigen is expressed on a variety of carcinomas. The purification of 5T4 antigenic molecules is described from term syncytiotrophoblast by a combination of lectin- and immunoaffinity chromatography and gel filtration giving up to 10,000-fold purification with 70% yield. The antigen is carried by non-associated glycoprotein molecules with an apparent molecular weight of 72 kDa on SDS-PAGE and a neutral pI. Removal of N-linked sugars by N-glycanase reveals a core protein of 42 kDa. Treatment with enzymes that cleave O-linked sugars does not substantially alter the molecular size. The native 5T4 molecules are very resistant to proteolysis until the N-linked sugars are removed or the glycoprotein is denatured and reduced. Glycopeptides generated by these approaches will be suitable for amino acid sequencing.

Publication types

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

MeSH terms

  • Antigens, Tumor-Associated, Carbohydrate / analysis
  • Antigens, Tumor-Associated, Carbohydrate / isolation & purification*
  • Chromatography, Affinity / methods
  • Chromatography, Gel / methods
  • Electrophoresis, Polyacrylamide Gel / methods
  • Humans
  • Microvilli / immunology
  • Molecular Weight
  • Precipitin Tests / methods
  • Trophoblasts / immunology
  • Trophoblasts / ultrastructure


  • Antigens, Tumor-Associated, Carbohydrate