Role of protein conformation and weak interactions on gamma-gliadin liquid-liquid phase separation

Wheat storage proteins, gliadins, were found to form in vitro condensates in 55% ethanol/water mixture by decreasing temperature. The possible role of this liquid-liquid phase separation (LLPS) process on the in vivo gliadins storage is elusive and remains to be explored. Here we use gamma-gliadin as a model of wheat proteins to probe gliadins behavior in conditions near physiological conditions. Bioinformatic analyses suggest that gamma-gliadin is a hybrid protein with N-terminal domain predicted to be disordered and C-terminal domain predicted to be ordered. Spectroscopic data highlight the disordered nature of gamma-gliadin.We developed an in vitro approach consisting to first solubilize gamma-gliadin in 55% ethanol (v/v) and to progressively decrease ethanol ratio in favor of increased aqueous solution. Our results show the ability of gamma-gliadin to self-assemble into dynamic droplets through LLPS, with saturation concentrations ranging from 25.9 mu M +/- 0.85 mu M (35% ethanol (v/v)) to 3.8 mu M +/- 0.1 mu M (0% ethanol (v/v)). We demonstrate the importance of the predicted ordered C-terminal domain of gamma-gliadin in the LLPS by highlighting the protein condensates transition from a liquid to a solid state under reducing conditions. We demonstrate by increasing ionic strength the role displayed by electrostatic interactions in the phase separation. We also show the importance of hydrogen bonds in this process. Finally, we discuss the importance of gliadins condensates in their accumulation and storage in the wheat seed

The influence of protein-chemical features on the skin sensitising capacity of five different wheat products: A dose-response study in brown Norway rats

International audienc

The influence of protein-chemical features on the skin sensitising capacity of five different wheat products: A dose-response study in brown Norway rats

International audienc

Data on agronomic traits, biochemical composition of lipids, proteins and polysaccharides and rheological measurement in a brown mustard seed collection

International audienceThe data were collected from a brown mustard seeds collection of 18 accessions during two years and in three distinct sites of production in France. The 18 accessions of mustard seeds were selected to be representative of genetic, agronomical and technological variabilities. All accessions were produced in the "Bourgogne " area. This article describes agronomical data (PMG, yield), genotyping data, global composition of mustard seeds (lipids, proteins and polysaccharides) and fine composition of the previous macronutrients potentially involved in the technological properties (fatty acids, storage proteins and osidic composition of polysaccharides). Additional data regarding the potential rheological property of each accessions were also reported. These data can be reused by food industries, breeders and geneticists in order to understand pedoclimatic effects (year and location) and the relation between mustard seed composition and the end uses properties (paste mustard quality)

Effect of Cultivars, Environment, and Year on Agronomic Traits, Biochemical Composition of Major Constituents (Lipids, Proteins, and Polysaccharides), and Rheological Properties of Seeds in Brassica juncea

International audienceIn order to provide varieties of Brassica juncea that meet agronomic and technological qualities, it is necessary to define criteria that are predictive of the quality of the finished product. The objective of our study is to characterize the macromolecula r components of the mustard seed in order to identify the compositional profile responsible for the technological quality of mustard pastes. A collection of cultivars that maximizes genetic and technological diversity were grown on three plots and over two years. Our results showed (i) the impact of the genetic and pedoclimatic factors on seed macromolecular components and on rheological properties estimated by measuring the flow in a Bostwick consistometer, and (ii) the potential role of seed storage proteins and cell wall polysaccharides in the mustard paste consistency. Data analyses allow us to propose new criteria for evaluating the technological quality of seeds and to identify interesting genotypes as candidates for future breeding programs