PURIFICATION OF MONOCLONAL-ANTIBODIES BY EPITOPE AND MIMOTOPE AFFINITY-CHROMATOGRAPHY

Murine monoclonal antibodies raised against the carcinoma-associated M UC1 mucin have applications in the diagnosis and therapy of human canc er. Many of these antibodies define linear epitopes of three, four or five amino acids within an immunodominant region of the MUC1 protein c ore. Various synthetic peptides which incorporated this region were pr epared and covalently Linked to agarose beads for use as affinity matr ices. An unrelated peptide was identified as a mimotope for one of the anti-MUC1 antibodies using phage display technologies and this was al so evaluated as a potential ligand in an affinity matrix. Epitope affi nity chromatographic purification of an anti-MUC1 antibody was perform ed using hybridoma tissue culture supernatants as sample. Following sa mple application and column washing, antibody was desorbed from the ma trix by gradient elution with increasing concentrations of NaSCN. The procedure has proved efficient for the purification of anti-MUC1 antib odies and the concentration of NaSCN required for antibody desorption gives a measure of the relative binding affinity of the antibody for t he peptide epitope matrix so that separation strategies may be optimis ed. (C) 1997 Elsevier Science B.V.