Publication no. C-2001-0608-01R |  VIEW ARTICLE

Purification and Partial Characterization of an Endoxylanase Inhibitor from Barley.

H. Goesaert (1,2), W. Debyser (1), K. Gebruers (1), P. Proost (3), J. Van Damme (3), and J. A. Delcour (1). (1) Laboratory of Food Chemistry, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium. (2) Corresponding author. Phone: (+32)-16-321634. Fax: (+32)-16-321997. E-mail: <hans.goesaert@agr.kuleuven.ac.be> (3) Laboratory of Molecular Immunology, Rega Institute, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium. Cereal Chem. 78(4):453-457. Accepted March 19, 2001. Copyright 2001 American Association of Cereal Chemists, Inc.

Hordeum vulgare L. xylanase inhibitor (HVXI), an endoxylanase inhibitor with a protein structure, was purified to homogeneity from barley (Hordeum vulgare L.). HVXI is a nonglycosylated monomeric protein, with a molecular weight of approximately 40,000 and a pI > 9.3. Although it inhibits different endoxylanases to a varying degree, the activities of an alpha-L-arabinofuranosidase and a beta-D-xylosidase were not inhibited. Apparently, HVXI occurs in two molecular forms. These characteristics and the N-terminal sequences of the composing polypeptides show that HVXI is homologous with Triticum aestivum L. xylanase inhibitor I, an endoxylanase inhibitor from wheat flour.