Gospodarczyk W, Kozak M
Department of Macromolecular Physics, Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, PL61614 Poznan, Poland.
Colloid Polym Sci. 2015;293(10):2855-2866. doi: 10.1007/s00396-015-3671-z. Epub 2015 Jul 8.
Gemini surfactants and their interactions with proteins have gained considerable scientific interest, especially when amyloidogenic proteins are taken into account. In this work, the influence of two selected dicationic (gemini) surfactants (3,3'-[1,8-(2,7-dioxaoctane)]bis(1-dodecylimidazolium) chloride and 3,3'-[1,12-(2,11-dioxadodecane)]bis(1-dodecylimidazolium) chloride) on two model proteins, bovine serum albumin (BSA) and hen egg white lysozyme (HEWL), have been investigated. A pronounced and sophisticated influence on BSA structure has been revealed, including a considerable change of protein radius of gyration as well as substantial alteration of its secondary structure. Radius of gyration has been found to rise significantly with addition of surfactants and to fall down for high surfactants concentration. Similarly, a remarkable fall of secondary structure (α-helix content) has been observed, followed by its partial retrieval for high surfactants concentration. A strong aggregation of BSA has been observed for a confined range of surfactants concentrations as well. In case of HEWL-gemini system, on the other hand, the protein-surfactant interaction was found to be weak. Molecular mechanisms explaining such behaviour of protein-surfactant systems have been proposed. The differences of properties of both studied surfactants have also been discussed.
双子表面活性剂及其与蛋白质的相互作用已引起了相当大的科学关注，尤其是在考虑到淀粉样蛋白的情况下。在这项工作中，研究了两种选定的双阳离子（双子）表面活性剂（3,3'-[1,8-(2,7-二氧杂辛烷)]双(1-十二烷基咪唑鎓)氯化物和3,3'-[1,12-(2,11-二氧杂十二烷)]双(1-十二烷基咪唑鎓)氯化物）对两种模型蛋白质，即牛血清白蛋白（BSA）和鸡蛋清溶菌酶（HEWL）的影响。已揭示出对BSA结构有显著且复杂的影响，包括蛋白质回转半径的相当大变化以及其二级结构的实质性改变。发现随着表面活性剂的添加，回转半径显著增加，而在高表面活性剂浓度下则下降。同样，观察到二级结构（α-螺旋含量）显著下降，随后在高表面活性剂浓度下部分恢复。在一定范围的表面活性剂浓度下也观察到了BSA的强烈聚集。另一方面，在HEWL-双子体系中，发现蛋白质与表面活性剂的相互作用较弱。已提出了解释蛋白质-表面活性剂体系这种行为的分子机制。还讨论了两种研究的表面活性剂性质的差异。
