Role of Non-prolamin Proteins and Low Molecular Weight Redox Agents in Protein Folding and Polymerization in Wheat Grains and Influence on Baking Quality Parameters

Abstract

The various enzyme systems and low molecular weight (LMW) redox agents are related to the folding and polymerization of prolamins in the ripening wheat grains and the formation of baking quality. Protein disulfide isomerases (PDIs) and cyclophylins accelerate "correct" folding of prolamins, which is most likely necessary for the subsequent formation of the macromolecular structure of the gluten protein matrix. PDIs are also involved in the polymerization of prolamins, catalyzing the oxidation of protein sulfhydryl groups. Molecular chaperone binding BiP protein facilitates folding of prolamins, with its role increasing in the stressful conditions. Reducing systems of thioredoxin and glutaredoxin, LMW redox pairs GSH/GSSG and Asc/DHAsc, thiol oxidases, and lipoxygenases (LOXs) regulate redox balance and the rate of polymerization of prolamins at the different stages of grain ripening. Additionally, LOX is probably involved in the protein-starch-lipid interactions between the starch granule and the protein matrix, mediated by puroindolines, determining the formation of grain texture. It is assumed that the high variability of baking quality in different environmental conditions is due to the interaction of labile enzyme systems with the storage proteins in the developing wheat caryopsis.

Technological Quality and Nutritional Value of Two Durum Wheat Varieties Depend on Both Genetic and Environmental Factors

“…A balance of oxidation−reduction in wheat grain is important for the polymerization of glutenins subunits, an important step in the formation of the gluten protein network with influence upon final gluten quality. 52 The protein superfamilies of thiol oxidoreductases, thioredoxins, and their functional analogues, glutaredoxins, play a key role in maintaining the intracellular SS/SH redox balance; they catalyze the reaction of dithiol−disulfide exchange or the removal of glutathione from the mixed disulfide protein− GSH. 53 Thus, the different modulation of such proteins in Saragolla with respect to Cappelli, in the two years of cultivation, could influence also grain quality.…”

How Foliar Fungal Diseases Affect Nitrogen Dynamics, Milling, and End-Use Quality of Wheat

“…This is because, after that, the accumulation of reserve proteins accounting for the highest percentage of the total amount at maturity starts (Stone and Savin, 1999;Triboi et al, 2003). There are suggestions in the literature about the influence of certain albumins on rheological properties of wheat flour dough, especially those associated with water absorption and resistance to extension (Osipova et al, 2012;Tomić et al, 2015). However, gluten proteins are primarily responsible for the viscoelastic properties of dough and ultimately the processing and enduse quality of wheat.…”

Distribution of Wheat Protein Components Under Different Genetic Backgrounds and Environments

“…These proteins are mainly present in the aleuronic layer and embryo and include many enzymes and regulatory proteins. While the influence of gluten proteins on bread-making quality of wheat is extensively studied, a smaller number of studies dealing with the influence of AG as non-gluten proteins on wheat quality (Gao et al, 2009;Osipova et al, 2012).…”