Publication no. C-1998-0105-05R |  VIEW ARTICLE

Isolation and Functionality Testing of Low Molecular Weight Glutenin Subunits.

M. J. Sissons (1), F. Bekes (2), and J. H. Skerritt (1,3). (1) CSIRO Division of Plant Industry, GPO Box 1600, Canberra, ACT 2601 Australia. (2) CSIRO Division of Plant Industry, North Ryde, NSW 2113 Australia. (3) Corresponding author. E-mail: <J.Skerritt@pi.csiro.au> Fax + 61 2 6246 5351/5000. Phone: + 61 2 6246 5350. Cereal Chem. 75(1):30-36. Accepted September 14, 1997. Copyright 1998 by the American Association of Cereal Chemists, Inc.

Various protein fractionation techniques have been applied to the isolation and purification of milligram quantities of low molecular weight glutenin subunits (LMW-GS). No single technique was applicable to the purification of the majority of the subunits. Partial purification of certain LMW-GS was obtained using ion-exchange chromatography and reversed-phase HPLC. Preparations containing alpha- and gamma-type subunit sequences did not strengthen dough when incorporated into a base flour, whereas preparations containing a subunit with an N-terminal methionine residue (METSHIPGL-) did. Using preparative isoelectric focusing over a narrow pH range, it was possible to purify (to approximately 90% purity) a B subunit that also had the N-terminal sequence of METSHIPGL-. This polypeptide, when incorporated into a base flour, had a dough strengthening effect in mixing trials, but less so than an equivalent amount of a high molecular weight glutenin subunit.