A B72.3 Second-Generation-Monoclonal Antibody (CC49) Defines the Mucin-Carried Carbohydrate Epitope Galβ(1—3) [NeuAcα(2—6)]GalNAc

Abstract

Mucus glycoproteins from bovine seminal plasma were demonstrated to express the MAbs CC49- and B72.3-defined epitopes on TAG 72 antigen. Inhibition studies with reductively cleaved mucin O-glycans from bovine seminal plasma and submaxillary glands revealed that CC49 binds specifically to a core-type sialyl-oligosaccharide alditol (fraction 2c), which could be defined with regard to its primary structure by FAB- and EI-mass spectrometry combined with methylation analysis: (formula; see text) Structurally related alditols NeuAc alpha(2-6)-GalNAc-ol, Gal beta(1-3)GalNAc-ol, NeuAc alpha(2-3)-Gal beta(1-3) [NeuAc alpha(2-6)] GalNAc-ol, GlcNAc beta(1-3) [NeuAc alpha(2-6)] GalNAc-ol or NeuAc alpha(2-3) Gal beta(1-3)GalNAc-ol were not inhibitory.