Structural analysis of N-glycans from yellow lupin (Lupinus luteus) seed diphosphonucleotide phosphatase/phosphodiesterase

N-Linked oligo saccharide chains released by hydrazinolysis from yellow lup in seed diphosphonucleotide phosphatase/phosphodiesterase were fluorescence labeled and separated by high performance liquid chromatography (GlycoSep N and GlycoSep H columns). Exoglycosidase sequencing elucidated the structu res of 24 separated N-glycans. Thirty percent of isolated glycans were foun d to be of high-mannose type (three to eight mannosyl residues), 42% were c omplex type and 26% belonged to paucimannosidic type. Among complex type gl ycans, structures with Lewis(a) epitope were identified. It is very unusual to find all types of plant N-glycans in one protein, Possible reasons for such a broad spectrum of N-glycan structures are discussed. (C) 2000 Elsevi er Science B.V. All rights reserved.