Initial immunochemical characterization of MX35 ovarian cancer antigen

Gynecol Oncol. 1997 Nov;67(2):188-92. doi: 10.1006/gyno.1997.4846.


Monoclonal antibody (mAb) MX35 reacts with approximately 90% of ovarian epithelial cancers and has been studied in localization and biodistribution trials in ovarian cancer patients. This study shows that mAb MX35 recognizes a cell surface antigen of about 95,000 D on OVCAR-3 ovarian cancer cells. The antigen could be immunoprecipitated from lysates of cells metabolically labeled with [3H]glucosamine and it bound to concanavalin A and wheat germ agglutinin lectins, showing that it is a glycoprotein. MX35 antigen can also be detected in detergent lysates of OVCAR-3 cells by Western blotting. Using this technique the MX35 epitope(s) was shown to be heat stable but susceptible to reduction by 2-mercaptoethanol. Protease digestion of the antigen resulted in smaller fragments (42-52 kDa) that still reacted with antibody. We conclude that MX35 antigen is a 95 kDa glycoprotein, stabilized by disulfide bonds, with a large protease-resistant region that carries the MX35 epitopes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antigens, Neoplasm / analysis*
  • Antigens, Neoplasm / chemistry
  • Antigens, Neoplasm / immunology
  • Epitopes
  • Female
  • Humans
  • Molecular Weight
  • Ovarian Neoplasms / immunology*
  • Precipitin Tests
  • Tumor Cells, Cultured


  • Antigens, Neoplasm
  • Epitopes