Complete structure of the carbohydrate moiety of stem bromelain. An application of the almond glycopeptidase for structural studies of glycopeptides

Abstract

Asparagine-linked oligosaccharides of stem bromelain glycopeptides were quantitatively released by digestion with the almond glycopeptidase which cleaves beta-aspartylglycosylamine linkage in glycopeptides with oligopeptide moieties. The primary structures of the two oligosaccharide components, (Man)3(Xyl)1(Fuc)1(GlcNAc)2 and (Man)2-(Xyl)1(Fuc)1(GlcNAc)2 were elucidated as Man alpha 1 leads to 6Man alpha 1 leads to 6[Xyl beta 1 leads to 2]Man beta 1 leads to 4GlcNAc beta 1 leads 4[Fuc alpha 1 leads to 3]GlcNAc and Man alpha 1 leads to 6[Xyl beta 1 leads to 2]Man beta 1 leads to 4 GlcNAc beta 1 leads to 4[Fuc alpha 1 leads to 3] GlcNAc, respectively.