Li Jingfang, Li Xiangyi, Jiang Fengrui, Li Xiaodong, Xie Xiaoming, Wu Lixin, Wang Liyan, Lee Myongsoo, Li Wen
State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Qianjin Avenue 2699, Changchun, 130012, P. R. China.
Key Laboratory of Functional Inorganic Material Chemistry (MOE), School of Chemistry and Materials Science, Heilongjiang University, No. 74, Xuefu Road, Nangang District, Harbin, 150080, P. R. China.
Chemistry. 2017 Sep 27;23(54):13510-13517. doi: 10.1002/chem.201702809. Epub 2017 Aug 29.
A series of cationic peptides with alternating hydrophilic and hydrophobic residues were elaborately designed and synthesized. These kinds of short peptides with protonated lysine groups can interact with anionic polyoxometalate nanoclusters through multivalent ionic bonds and hydrogen bonds, resulting in the formation of helical polyoxometalate arrays in aqueous solution. Fourier transform infrared (FTIR) spectroscopy, circular dichroism (CD), transmission electron microscopy (TEM), and dynamic light scattering (DLS) were utilized to characterize the self-assembled structures. TEM revealed that the polyoxometalate clusters form periodic arrays within the helical nanofibers. This work reports that the handedness of the helical fibers was attributed to the precise chirality expression of peptides. The l-type peptide directed the formation of left-handed polyoxometalate arrays, whereas right-handed polyoxometalate arrays were observed when the peptide was constituted by d-amino acids. It was also found that the pitch of the helical nanofibers is inversely proportional to the hydrophobicity of peptides with less hydrophobicity giving a larger helical pitch.
精心设计并合成了一系列具有交替亲水性和疏水性残基的阳离子肽。这些带有质子化赖氨酸基团的短肽可通过多价离子键和氢键与阴离子多金属氧酸盐纳米团簇相互作用，从而在水溶液中形成螺旋状多金属氧酸盐阵列。利用傅里叶变换红外（FTIR）光谱、圆二色性（CD）、透射电子显微镜（TEM）和动态光散射（DLS）对自组装结构进行表征。TEM显示多金属氧酸盐团簇在螺旋状纳米纤维内形成周期性阵列。这项工作报道螺旋纤维的手性归因于肽的精确手性表达。l型肽引导形成左手性多金属氧酸盐阵列，而当肽由d-氨基酸构成时，则观察到右手性多金属氧酸盐阵列。还发现螺旋状纳米纤维的螺距与肽的疏水性成反比，疏水性较小的肽具有较大的螺旋螺距。
