1C5 antigen: cancer-associated protein expressed by cervical adenocarcinomas and beta-casein

The monoclonal antibody 1C5 reacts with an antigenic determinant present in 90% of the cases of adenocarcinoma of the uterine cervix. The antigen defined by the 1C5 antibody exhibits immunological characteristics similar to those of skim milk (bovine buttermilk). 1C5-defined antigen obtained from tumor extract and skim milk binds specifically to wheat germ agglutinin (WGA) lectin. The 1C5-defined antigenic activity of a WGA lectin-bound fraction was eluted at 0.7-0.8 M NaCl off a Mono Q column. Use of an inhibition assay and a dot immunobinding assay revealed that the antigenic epitope defined by the 1C5 MoAb from skim milk exists within the first 28 amino acids of the beta-casein peptide.