Ramos Laurence, Banc Amélie, Louhichi Ameur, Pincemaille Justine, Jestin Jacques, Fu Zhendong, Appavou Marie-Sousai, Menut Paul, Morel Marie-Hélène
Laboratoire Charles Coulomb (L2C), Univ. Montpellier, CNRS, Montpellier, France.
Ingénierie des Agro-polymères et Technologies Emergentes (IATE), Univ. Montpellier, CIRAD, INRAE, Montpellier SupAgro, Montpellier, France.
J Phys Condens Matter. 2021 Feb 5;33(14). doi: 10.1088/1361-648X/abdf91.
We investigate the structure of gluten polymer-like gels in a binary mixture of water/ethanol, 50/50 v/v, a good solvent for gluten proteins. Gluten comprises two main families of proteins, monomeric gliadins and polymer glutenins. In the semi-dilute regime, scattering experiments highlight two classes of behavior, akin to standard polymer solution and polymer gel, depending on the protein composition. We demonstrate that these two classes are encoded in the structural features of the proteins in very dilute solution, and are correlated with the presence of proteins assemblies of typical size tens of nanometers. The assemblies only exist when the protein mixture is sufficiently enriched in glutenins. They are found directly associated to the presence in the gel of domains enriched in non-exchangeable H-bonds and of size comparable to that of the protein assemblies. The domains are probed in neutron scattering experiments thanks to their unique contrast. We show that the sample visco-elasticity is also directly correlated to the quantity of domains enriched in H-bonds, showing the key role of H-bonds in ruling the visco-elasticity of polymer gluten gels.
我们研究了在水/乙醇（体积比50/50）二元混合物（面筋蛋白的良溶剂）中类面筋聚合物凝胶的结构。面筋由两类主要蛋白质组成，即单体麦醇溶蛋白和聚合物麦谷蛋白。在半稀溶液体系中，散射实验根据蛋白质组成突出了两类行为，类似于标准聚合物溶液和聚合物凝胶。我们证明，这两类行为在极稀溶液中蛋白质的结构特征中就已编码，并与典型尺寸为数十纳米的蛋白质聚集体的存在相关。这些聚集体仅在蛋白质混合物中麦谷蛋白充分富集时才存在。它们被发现与凝胶中富含不可交换氢键且尺寸与蛋白质聚集体相当的区域直接相关。由于这些区域具有独特的对比度，因此在中子散射实验中得以探测。我们表明，样品的粘弹性也与富含氢键的区域数量直接相关，这表明氢键在决定聚合物面筋凝胶的粘弹性方面起着关键作用。
