EFFECT OF GLYCOSYLATION OF A SYNTHETIC MUC1 MUCIN-CORE-RELATED PEPTIDE ON RECOGNITION BY ANTI-MUCIN ANTIBODIES

Human epithelial mucins are heterogeneously glycosylated proteins asso ciated with breast and ovarian cancer. Several peptide-reactive anti-m ucin MUC1 monoclonal antibodies are used in experimental sind diagnost ic assays but it is not known how glycosylation of the mucin influence s antibody recognition. In this report we show that increasing glycosy lation of a synthetic 25-amino acid fragment of the MUC1 core protein with N-acetylgalactosamine (GalNAc) elicits different responses in its recognition by two anti-MUC1 antibodies, C595 and HMFG1. We propose t hat increasing glycosylation of the synthetic mucin fragment produces an alteration in the structure of the epitope which enhances binding i n C595, but not in HMFG1.