Crystal Structure of Wheat Glutaredoxin and Its Application in Improving the Processing Quality of Flour

Abstract

Glutaredoxin (Grx) is a ubiquitous oxidoreductase that plays a vital role in maintaining cellular redox homeostasis. In comparison to Grx from other organisms, plant Grx is unique in that it has many isoforms, which, thus, suggests probably diverse functions and mechanisms. Therefore, structure−function characterization of plant Grx is necessary to have indepth knowledge and explore its application in industry. In this study, wheat Grx (wGrx) was overexpressed and purified and the crystal structure of wGrx was determined at 2.94 Å resolution. Interestingly, the structure for the first time captured both the oxidized form and the transient state of reduced−oxidized wGrx in a crystal. The mutagenesis of wGrx suggests that it adopts a monothiol catalytic mechanism. wGrx has the ability to reduce wheat thioredoxin (wTrx), and this is the first example of the reduction of thioredoxin subgroup h class II by Grx. Flour farinograph and dynamic rheological analysis showed that wGrx together with wTrx has a positive effect on dough formation, which is probably attributed to the increased sodium dodecyl sulfate (SDS)-insoluble gluten macropolymer (GMP) through increasing the intermolecular disulfide bond induced by the wGrx−wTrx system. The results indicate great potential of wGrx−wTrx as a novel synergetic enzymatic additive and may be employed to fine-tune the processing performance of food related to the redox reaction.

Behavioral Changes in Glutenin Macropolymer Fermented byLactobacillus plantarumLB-1 to Promote the Rheological and Gas Production Properties of Dough

“…The storage modulus is a measure of the ability of an object to resist elastic deformation, and the loss modulus reflects the viscosity of the material. 45 Figure 6 shows that G′ was significantly (p < 0.05) higher than G″ in all the doughs, indicating that elasticity is dominant, and all the doughs possessed solidlike properties. Compared to DY, the changes in G′ and G″ of DOA, DLB-1, and DYLB-1 were more obvious.…”

“…The dynamic rheological parameters, including the storage modulus ( G ′) and loss modulus ( G ″), of different doughs during the fermentation stage are depicted in Figure . The storage modulus is a measure of the ability of an object to resist elastic deformation, and the loss modulus reflects the viscosity of the material Figure shows that G ′ was significantly ( p < 0.05) higher than G ″ in all the doughs, indicating that elasticity is dominant, and all the doughs possessed solidlike properties.…”

Characterization and Exploration of Recombinant Wheat Catalase for Improvement of Wheat-Flour-Processing Quality

“…8,11 It was reported that wheat glutaredoxin together with wheat thioredoxin has a positive effect on flour and dough properties and bread making. 12 Catalase (EC 1.11.1.6), which catalyzes the decomposition of hydrogen peroxide, mostly exists in aerobic living organisms to protect the cells from oxidative stress triggered by overproduced hydrogen peroxide. 13 Furthermore, catalase also catalyzes the peroxidation of phenols, formic acid, formaldehyde, and alcohols.…”

“…Actually, in recent years increasing evidence has shown that redox enzymes could affect the processing quality of flour and dough. Previous research showed that wheat endoplasmic-reticulum oxidoreductin 1 (wEro1), glucose oxidase, and pyranose oxidase could enhance mixing characteristics and viscoelastic properties of dough. , It was reported that wheat glutaredoxin together with wheat thioredoxin has a positive effect on flour and dough properties and bread making …”