【作者】 刘泽宇； 阎云； 黄建滨；

【Author】 Zeyu Liu;Yun Yan;Jianbin Huang;College of Chemistry and Molecular Engineering,Peking University;

【机构】 胶体与界面化学实验室北京大学化学与分子工程学院；

【摘要】 为了自下而上构建具备响应性的自组装超分子体系,多种弱相互作用的协同驱动组装是有力的手段,但由于不同弱相互作用间的相互影响,不易有针对性、有序的构建组装,这也成为了这一领域的挑战,因此,合理的分子设计是组装行为可预测、易调控的基础。依托芳香基团良好的定向能力和肽键之间的作用,芳香化肽两亲分子被广泛的应用于构筑超分子材料[1]。基于此理念,我们设计了一种芳香化寡肽磷酸酯(aromaticoligopeptidesphosphates)分子FmocOPP,为芴甲氧羰基(Fmoc)修饰的磷酸化短肽,分子中含有π-π作用、氢键作用、静电作用位点,可通过不同的外部刺激针对性调控,组装体系可实现多因子的响应。在pH=7.0条件下,FmocOPP分子的磷酸头基带较多电荷,分子间斥力强,不易形成组装体;当pH降低至6.0时,磷酸头基部分质子化,静电斥力减弱,临界聚集浓度降低,此时会出现囊泡结构;若此时以磷酸酶处理体系,消除分子结构中的磷酸头基,则会彻底消除静电作用,分子彼此靠近,π-π作用驱动形成一维组装结构,显示出手性信号。由于带电磷酸头基的存在,使得静电作用主导组装行为,控制静电作用可间接调控π-π作用在组装中的地位,因此pH、无机盐、酶的刺激均可通过调控静电作用显著调控组装体形貌和性质。更多还原

【Abstract】 The cooperation of multi-intermolecular interactions is considered as a significant approach to the bottom-up fabrication of responsive supramolecular self-assembly system. However, due to the interference among multi-intermolecular interactions, the well-organized modulation of these systems remains a challenging task. Resonable molecular design is the base of prediction and modulation of self-assemble behaviors. Due to the well-organized of π-π interactions and peptide bond interactions, aromatic peptides are widely used as the building blocks for such kind of supramoleculars. We designed an aromatic oligopeptides phosphates, FmocOPP, which contain sites of π-π interactions, hydrogen bonds and electrostatic interactions. The self-assemblies of FmocOPP can be modulated by several kinds of external stimulus. At the condition of pH=7.0, the phosphoryl group is chagered, electrostatic repulsion will be the inhibition of assembly. When pH decreases to 6.0, the electrostatic repulsion among phosphoryl groups is partly shielded and vesicles will appear. Further more, enzyme treatment will completely remove the phosphoryl groups, which means electrostatic repulsion disappear and π-π interactions will induce 1 D assemblies as primary driven interaction because moleculars are close enough, besides, this kind of tube-like assemblies have CD signals. Modulating electrostatic repulsion can indirectly switch π-π interactions into primary driven interactions, therefore, all pH, inorganic ions and enzyme stimulus can modulate the aseembly and its properties significantly.更多还原