Mass spectrometry of a human tumor glycolipid antigen being defined by mouse monoclonal antibody NS-19-9.

With an antibody-to-chromatogram binding assay to follow the preparation a glycolipid was isolated from human pancreatic carcinoma using a mouse monoclonal antibody of apparent specificity for gastrointestinal tumors. Direct probe mass spectrometry of three derivatives established the sugar sequence as NeuAc-hexose-(fucose)N-acetylhexosamine-hexose-hexose and the ceramide to be composed mainly of phytosphingosine and 16-24 carbon 2-hydroxy fatty acids. NMR spectroscopy of two of the derivatives made likely the presence of the sequence Gal beta 1 leads to 3GlcNAc(4 comes from 1 alpha Fuc)beta 1 leads to, which is the blood group Lewis a determinant. This is in agreement with recent results from degradation studies.