Publication no. C-2000-1205-01R |  VIEW ARTICLE

In Vitro Binding of Puroindolines to Wheat Starch Granules.

Helle A. Bloch (1,2), Helen F. Darlington (1), and Peter R. Shewry (1,3). (1) IACR-Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol BS41 9AF, UK. (2) Present address: Department of Biochemistry and Nutrition, Seltofts Plads, Technical University of Denmark, Building 224, 2800 Lyngby, Denmark. (3) Corresponding author. Phone: +44 (0)1275 392181. E-mail: <peter.shewry@bbsrc.ac.uk> Cereal Chem. 78(1):74-78. Accepted August 17, 2000. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 2001.

Puroindoline (pin) preparations made from flours of hard and soft wheats contained a mixture of pin-a, 0.19/0.53 alpha-amylase inhibitor, and purothionins. Starch granule preparations from the same cultivars were treated with proteinase to remove surface proteins and incubated with solutions of the pin preparations. Binding of pin-a and purothionins but not the 0.19/0.53 inhibitor was observed with no apparent differences between the behavior of the pin preparations or starch granule preparations from hard or soft types. No binding was observed when several other proteins (bovine serum albumin, total albumins, a commercial preparation of wheat alpha-amylase inhibitors, and barley beta-amylase) were incubated with the starch granules under the same conditions, indicating that in vitro binding can be used to study specific starch granule and protein interactions.