Publication no. C-2002-0405-03R |  VIEW ARTICLE

Proteolytic Enzymes in Germinating Rye Grains.

Kristof Brijs (1,2), Isabel Trogh (1), Berne L. Jones (3), and Jan A. Delcour (1). (1) Laboratory of Food Chemistry, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium. (2) Corresponding author. Phone: (+32)-16-321582. Fax: (+32)-16-321997. E-mail: <kristof.brijs@agr.kuleuven.ac.be> (3) USDA-Agricultural Research Service, Cereal Crops Research Unit, 501 N. Walnut St., Madison, WI 53705. Cereal Chem. 79(3):423-428. Accepted January 14, 2002. Copyright 2002 American Association of Cereal Chemists, Inc.

The proteolytic activities during rye (Secale cereale L. ‘Humbolt’) grain germination were monitored using in-solution methods and one- and two-dimensional PAGE with gels that contained incorporated substrate proteins. The total proteolytic activity increased during the first three days of germination, but not after that. The proteinase activity was measured at pH 3.8, 6.0, and 8.0 in the presence and absence of class-specific proteinase inhibitors. This indicated that enzymes from all four proteinase classes were present during the germination process. Germinated rye grain contained mainly aspartic and cysteine proteinase activities that are especially active at pH 3.8. Serine- and metallo-proteinases were less abundant. Overall, the pattern of hydrolysis was very similar to that observed during barley and wheat germination.