Rafikova Anastasiya R, Milyaeva Olga Y, Loglio Giuseppe, Miller Reinhard, Wan Zhili, Noskov Boris A
Department of Colloid Chemistry, St. Petersburg State University, Universitetsky pr. 26, 198504 Saint Petersburg, Russia.
Institute of Condensed Matter Chemistry and Technologies for Energy, 16149 Genoa, Italy.
Polymers (Basel). 2025 Apr 16;17(8):1075. doi: 10.3390/polym17081075.
Although the formation of the layers of fibrillar aggregates at liquid-liquid and liquid-gas interfaces can significantly increase the stability of disperse systems, like foams and emulsions, any information on their structure and properties is rather limited. In the present work, surface properties of the adsorption layers of fibrils of intrinsically disordered β-casein are investigated. For unpurified dispersions of the fibrils of this protein, the dynamic surface elasticity proved to be close to the values for the native protein solutions. This behavior is typical for dispersions of fibrils of globular proteins. However, previously studied fibrils of another intrinsically disordered protein, κ-casein, do not demonstrate this similarity. The contribution of β-casein fibrils to the dynamic surface properties becomes noticeable only after the purification of the dispersions from impurities of high surface activity. The dynamic surface elasticity increases up to 48 mN/m after two purification cycles, i.e., to values 4 times higher than the steady-state values of native protein adsorption layers at the same protein bulk concentrations.
尽管在液-液和液-气界面形成的纤维状聚集体层可以显著提高泡沫和乳液等分散体系的稳定性，但关于它们的结构和性质的任何信息都相当有限。在本工作中，研究了内在无序的β-酪蛋白纤维吸附层的表面性质。对于这种蛋白质纤维的未纯化分散体，动态表面弹性被证明接近天然蛋白质溶液的值。这种行为对于球状蛋白质纤维的分散体来说是典型的。然而，先前研究的另一种内在无序蛋白质κ-酪蛋白的纤维并没有表现出这种相似性。只有在从高表面活性杂质中纯化分散体后，β-酪蛋白纤维对动态表面性质的贡献才变得明显。经过两个纯化循环后，动态表面弹性增加到48 mN/m，即在相同蛋白质本体浓度下，比天然蛋白质吸附层的稳态值高4倍。
