Structure determination of glycopeptide of beta-momorcharin

The structure of the N-linked oligosaccharide chain of beta-momorcharin, a ribosome-inactivating protein from the seeds of Momordica charantia Linn (C ucurbitaceae), was determined. A glycopeptide liberated by pronase digestio n of the glycoprotein was subjected to amino acid and neutral carbohydrate analysis to establish the composition of amino acid and sugar residues. The sequences and glycosylation linkages of the sugar and amino acid residues in the glycopeptide were determined as Man alpha 1-6(Xyl beta 1-2)-Man beta 1-4GlcNAc beta 1-4(Fuc alpha 1-3)-GlcNAc-Asn-Leu by 2D-NMR spectroscopy an d FAB-MS data.