A glycoprotein antigen which is generally characteristic of human carcinomas, regardless of the tissue associated with the carcinoma-human carcinoma antigen (HCA)-and which is generally not present on normal human cells. Immunodeterminant-containing fragments of HCA substantially separated from elements of HCA's naturally occurring environment are also disclosed. HCA is generally characterized by: a) a molecular weight in excess of 750,000; b) carbohydrate moieties characteristic of mucin-type glycoproteins and comprising a relatively high proportion of sialic acid, galactose, and N-acetylgalactosamine residues (e.g., at least 50% of the carbohydrate residues are sialic acid, galactose, or N-acetylgalactosamine residues); c) an isoelectric point below pH 3.0; d) presence generally on human carcinoma cells; e) absence generally from non-transformed human cells; f) at least one immunodeterminant that specifically reacts with anti-murine epiglycanin antibody AE3; and g) general insolubility in aqueous fluids (e.g., a phosphoric acid or an HCl solution) below pH 2.0. Also disclosed are antibodies to HCA, immunoassays for HCA and in vivo imaging using HCA-binding antibodies.
展开▼
