St Petersburg State University, 199034 St. Petersburg, Russia.
St Petersburg State University, 199034 St. Petersburg, Russia; All-Russia Research Institute for Agricultural Microbiology, 196608 St. Petersburg, Russia.
Biophys Chem. 2024 Apr;307:107166. doi: 10.1016/j.bpc.2023.107166. Epub 2024 Jan 5.
Spread layers of amorphous aggregates of the structural domain of plant protein vicilin, cupin-1.1, at the water - air interface were studied by the surface tensiometry, dilational surface rheology, Brewster angle and atomic force microscopy. The layer properties differed strongly from the results for the layers of previously studied proteins. The dependency of the dynamic elasticity of the layer on surface pressure had two local maxima with the second peak being four times higher than the first one. In the region of the first maximum the obtained results are similar to those for dispersions of polymer microgels with a hairy corona. At the beginning of surface compression separate threads of the corona are stretched along the surface and the surface elasticity increases. The further compression results in the formation of loops and tails leading to a decrease of the elasticity. The second local maximum of the dynamic surface elasticity is presumably caused by the interactions of the rigid cores of the aggregates leading finally to the formation of multilayer structures at high surface pressures. In this case, the surface elasticity starts to decrease as a result of the segment exchange between different layers at the interface.
采用表面张力法、动态表面流变法、偏光显微镜和原子力显微镜研究了植物蛋白伴球蛋白结构域、cupin-1.1 在水-气界面的无定形聚集层。与之前研究的蛋白质的层性质相比，该层的性质差异很大。层的动态弹性对表面压力的依赖性有两个局部最大值，第二个峰值比第一个峰值高四倍。在第一个最大值的区域，得到的结果与具有绒毛冠的聚合物微凝胶分散体的结果相似。在表面压缩的开始，冠的单独纤维沿表面被拉伸，表面弹性增加。进一步的压缩导致形成环和尾，导致弹性降低。动态表面弹性的第二个局部最大值可能是由聚集物的刚性核之间的相互作用引起的，最终导致在高表面压力下形成多层结构。在这种情况下，由于界面不同层之间的片段交换，表面弹性开始下降。
