Soft Matter and Molecular Biophysics Group, Department of Applied Physics University of Santiago de Compostela, Campus Sur s/n, 15782, Santiago de Compostela, Spain.
J Phys Chem B. 2011 May 19;115(19):6304-11. doi: 10.1021/jp200835j. Epub 2011 Apr 14.
This study describes the adsorption behavior of mixed protein/surfactant systems at the air-water interface: specifically fibrinogen and the fluorinated and hydrogenated surfactants (C(8)FONa, C(8)HONa, and C(12)HONa). Surface tension techniques and atomic force microscopy (AFM) have been combined to investigate the adsorption behavior of these mixed systems. Interfacial rheology showed that fibrinogen has a low dilatational modulus at the air-water interface when compared to other proteins, suggesting the formation of a weak surface network. Fluorinated and hydrogenated surfactants severely decreased the dilatational modulus of the adsorbed fibrinogen film at the air-water interface. These measurements suggest the progressive displacement of fibrinogen from the air-water interface by both types of surfactants. However, in the case of fibrinogen/fluorinated surfactant systems, surface tension and dilatational rheology measurements suggest the formation of complexes with improved surface activity. AFM imaging of fibrinogen in the presence and absence of surfactants provided new information on the structure of mixed surface films, and revealed new features of the interaction of fibrinogen with hydrogenated and fluorinated surfactants. These studies suggest complexes formed between fibrinogen and fluorinated surfactants which are more surface active than fibrinogen, while the absence of interaction between fibrinogen and hydrogenated surfactants (C(8)HONa and C(12)HONa) results in compaction of the surface layer.
本研究描述了混合蛋白/表面活性剂体系在气-液界面上的吸附行为：特别是纤维蛋白原和氟化及氢化表面活性剂（C(8)FONa、C(8)HONa 和 C(12)HONa）。我们将表面张力技术和原子力显微镜（AFM）结合起来，研究了这些混合体系的吸附行为。界面流变学表明，与其他蛋白质相比，纤维蛋白原在气-液界面上的扩张模量较低，表明形成了较弱的表面网络。氟化和氢化表面活性剂严重降低了吸附在气-液界面上的纤维蛋白原膜的扩张模量。这些测量结果表明，这两种类型的表面活性剂逐渐取代了纤维蛋白原在气-液界面上的位置。然而，在纤维蛋白原/氟化表面活性剂体系中，表面张力和扩张流变学测量结果表明形成了具有改善表面活性的复合物。存在和不存在表面活性剂时的纤维蛋白原 AFM 成像提供了有关混合表面膜结构的新信息，并揭示了纤维蛋白原与氢化和氟化表面活性剂相互作用的新特征。这些研究表明，纤维蛋白原与氟化表面活性剂形成的复合物比纤维蛋白原具有更高的表面活性，而纤维蛋白原与氢化表面活性剂（C(8)HONa 和 C(12)HONa）之间不存在相互作用，导致表面层的压缩。
