Cereal Chem 45:486 - 495.  |  VIEW ARTICLE
Disulfide-Sulfhydryl Interchange Studies of Wheat Flour. II. Reaction of Glutathione.

T. Kuninori and B. Sullivan. Copyright 1968 by the American Association of Cereal Chemists, Inc. 

Radioactive glutathione (G35SH) was used as a tool for investigating disulfide-sulfhydryl interchange reactions in flour suspensions and doughs. Incorporation of G35SH, added at a level of 1 micron mol./g. flour, was not measurably increased in suspensions by greater alkalinity or by anaerobic conditions. The percent of label incorporated in the soluble and insoluble proteins in suspensions ranged from 10.5 to 25% under all conditions tested. The gluten proteins incorporated only 8.3 to 12.4%. When the same amount of G35SH was added to a dough, 29 and 35.4% of the isotope was incorporated in the protein after 5 and 30 min. of mixing. A dough containing 1 micro mol. of G35SH/g. flour was lyophilized and remixed with a large excess of glutathione (GSH). The acetic acid-soluble fraction was separated on Sephadex G-100; there was almost complete liberation of the incorporated label. That a GSH-linked hydrogen-transfer system is not involved was proved by adding GSH to synthetic flour made from vital wheat gluten and wheat starch. The same weakening effect was observed as in normal flour. Also, a heated flour used in a suspension gave the same results on counting as the unheated flour. These findings are discussed in relation to disulfide- sulfhydryl interchange.