楔形短肽表面活性剂A_3V_3D纳米自组装结构的表征及机理研究

Self-assembling Structure and Mechanism of a Wedge-shaped Peptide Detergent A_3V_3D

通过对传统短肽表面活性剂氨基酸序列的改良,设计了具有楔形几何结构的新型短肽表面活性剂A3V3D.圆二色谱(CD)分析表明,该短肽的二级结构为无规则卷曲,透射电子显微镜(TEM)和原子力显微镜(AFM)表征发现,该短肽在水溶液中能够发生有序的自组装,形成稳定的光滑平直的纳米纤维.芘探针荧光光谱分析显示,该短肽形成了疏水区并将芘分子包裹其中.由此推测A3V3D在其楔形几何结构的影响下,以柱状胶束的形式发生自组装,是一种新型的自组装短肽材料,说明了几何形状效应在控制短肽的自组装行为中起着关键作用.

A wedge-shaped peptide detergent A3V3 D was designed by changing the amino acid sequence of traditional peptide detergents. Although the secondary structure of this peptide is random coil as revealed by circular dichroism（CD） assessment, it can still undergo well-ordered self-assemble in water solution into stable, smooth and straight nanofibers, which are observed by transmission electron microscopy（TEM） and atomic force microscopy（ AFM ）. Pyrene probe fluorescence analysis indicated that it could form hydrophobic domains in which pyrene molecules were imbedded. It was believed that driven by its wedge-like geometrical shape, A3 V3 D undergoes self-assemble in the form of cylindrical micelles, making it a novel self-assembling peptide material, and indicating the critical role of geometrical shape effect in controlling the self-assembling behavior.