Departament d'Enginyeria Química, EEBE , Universitat Politècnica de Catalunya , C/Eduard Maristany, 10-14, Ed. I2 , 08019 Barcelona , Spain.
Barcelona Research Center for Multiscale Science and Engineering , Universitat Politècnica de Catalunya , Eduard Maristany, 10-14 , 08019 Barcelona , Spain.
Langmuir. 2018 Dec 18;34(50):15551-15559. doi: 10.1021/acs.langmuir.8b03378. Epub 2018 Nov 30.
The self-assembly behavior of a diphenylalanine amphiphile blocked at the C-terminus with a 9-fluorenylmethyl ester and stabilized at the N-terminus with a trifluoroacetate (TFA) anion, TFA·FF-OFm, has been examined. At low peptide concentration (0.5 mg/mL), long amyloid-like fibrils, which come from the fusion of two or more helical ribbons and/or thinner fibrils, organized in bundles or as individual entities are detected. Microbeam synchrotron radiation infrared spectroscopy has shown that TFA·FF-OFm molecules in amyloid-like fibrils arrange, forming antiparallel β-sheets. Alteration of the experimental conditions to prioritize the thermodynamic contribution with respect to the kinetic one in the self-assembly process inhibits the organization of amyloid-like structures in favor of the formation of conventional fibrous structures. On the basis of experimental observations, a structural model where the individual antiparallel β-sheets are oriented in parallel has been proposed for TFA·FF-OFm amyloid-like fibrils.
一种在 C 端被 9-芴甲氧羰基（FMOC）封闭、在 N 端被三氟乙酸（TFA）阴离子稳定的二苯丙氨酸两亲分子 TFA·FF-OFm 的自组装行为已经被研究。在低浓度（0.5mg/ml）下，检测到由两条或更多螺旋带和/或更细的纤维融合而成的长的类似淀粉样纤维，它们以束状或单个实体存在。微束同步辐射红外光谱表明，类似淀粉样纤维中的 TFA·FF-OFm 分子排列形成反平行 β-折叠。通过改变实验条件，优先考虑自组装过程中的热力学贡献而不是动力学贡献，抑制了类似淀粉样结构的形成，有利于形成常规纤维结构。基于实验观察，提出了一种结构模型，其中单个反平行β-折叠平行排列。
