The glycosylation of the aspartic proteinases from barley (Hordeum vulgare L.) and cardoon (Cynara cardunculus L.)

Eur J Biochem. 1997 Feb 1;243(3):695-700. doi: 10.1111/j.1432-1033.1997.t01-1-00695.x.


Plant aspartic proteinases characterised at the molecular level contain one or more consensus N-glycosylation sites [Runeberg-Roos, P., Tŏrmäkangas, K. & Ostman, A. (1991) Eur. J. Biochem. 202, 1021-1027; Asakura, T., Watanabe, H., Abe, K. & Arai, S. (1995) Eur. J. Biochem, 232, 77-83; Veríssimo, P., Faro, C., Moir, A. J. G., Lin, Y., Tang, J. & Pires, E. (1996) Eur. J. Biochem. 235, 762-768]. We found that the glycosylation sites are occupied for the barley (Hordeum vulgare L.) aspartic proteinase (Asn333) and the cardoon (Cynara cardunculus L.) aspartic proteinase, cardosin A (Asn70 and Asn363). The oligosaccharides from each site were released from peptide pools by enzymatic hydrolysis with peptide-N-glycanase A or by hydrazinolysis and their structures were determined by exoglycosidase sequencing combined with matrix-assisted laser desorption/ionization time of flight mass spectrometry. It was observed that 6% of the oligosaccharides from the first glycosylation site of cardosin A are of the oligomannose type. Modified type glycans with proximal Fuc and without Xyl account for about 82%, 14% and 3% of the total oligosaccharides from the first and the second glycosylation sites of cardosin A and from H. vulgare aspartic proteinase, respectively. Oligosaccharides with Xyl but without proximal Fuc were only detected in the latter proteinase (4%). Glycans with proximal Fuc and Xyl account for 6%, 86% and 92% of total oligosaccharides from the first and second glycosylation sites of cardosin A and from H. vulgare aspartic proteinase, respectively.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aspartic Acid Endopeptidases / chemistry
  • Aspartic Acid Endopeptidases / metabolism*
  • Carbohydrate Sequence
  • Glycosylation
  • Hordeum / chemistry
  • Hordeum / enzymology*
  • Hordeum / metabolism
  • Molecular Sequence Data
  • Oligosaccharides / chemistry
  • Oligosaccharides / isolation & purification
  • Oligosaccharides / metabolism
  • Plant Proteins / chemistry
  • Plant Proteins / metabolism*


  • Oligosaccharides
  • Plant Proteins
  • Aspartic Acid Endopeptidases