Identification of the S-Endo 1 endothelial-associated antigen

We have recently described a monoclonal antibody, S-Endo 1, recognizing a molecule constitutively expressed in all types of human endothelial cells. We showed that this protein around 118 kDa acid located at the endothelial cell-cell junction presented sequence identity with MUC18 described as a tumor marker in human melanoma. The difference in antibodies immunoreactivity and antigen molecular weight heterogeneity observed between various cell types strongly suggested S-Endo 1 antigen isoforms expression. (C) 1996 Academic Press, Inc.