Instituto de Física, Universidade de São Paulo , São Paulo 05314-970, Brazil.
Departamento de Biofísica, Universidade Federal de São Paulo , São Paulo 04023-062, Brazil.
Langmuir. 2018 Feb 6;34(5):2171-2179. doi: 10.1021/acs.langmuir.7b03869. Epub 2018 Jan 23.
In the present work, we investigate the effect of two short phenylalanine-based peptides on lipid membranes. A simplified model membrane composed of lecithin vesicles was used to incorporate different amounts of the two amino acid sequences, the dimmer l,l-diphenylallanine (FF) and the trimmer cysteine-diphenylallanine (CFF). Spectroscopic and scattering techniques were applied to probe in detail the structural behavior of lipid membranes in the presence of the peptides. The experimental results demonstrate that both peptides are located mainly at the interface of the membrane interacting with phosphate groups modifying membrane thickness and flexibility. The multilamellar structure of the vesicles is preserved with inclusion of small amounts of FF, accompanied by changes in membrane thickness and elasticity. Finally, a multi- to unilamellar transition is observed as a result of peptide self-association into a crystalline structure onto the membrane interface.
在本工作中，我们研究了两种短苯丙氨酸肽对脂质膜的影响。使用由卵磷脂囊泡组成的简化模型膜来掺入两种氨基酸序列的不同量，即二聚体 l,l-二苯丙氨酸（FF）和三聚体半胱氨酸-二苯丙氨酸（CFF）。应用光谱和散射技术详细探测脂质膜在肽存在下的结构行为。实验结果表明，两种肽都主要位于与磷酸基团相互作用的膜界面处，从而改变膜的厚度和柔韧性。当加入少量 FF 时，囊泡的多层结构得以保留，同时膜的厚度和弹性发生变化。最后，由于肽自组装成结晶结构并附着在膜界面上，观察到多至单层的转变。
