University of Trieste, Chem. Pharm. Sc. Dept., Via Giorgieri 1, 34127 Trieste, Italy.
Soft Matter. 2020 Nov 18;16(44):10151-10157. doi: 10.1039/d0sm01191f.
Amino acid stereoconfiguration has been shown to play a key role in the self-assembly of unprotected tripeptides into hydrogels under physiological conditions. Dramatic changes were noted for hydrophobic sequences based on the diphenylalanine motif from the formation of amorphous aggregates in the case of homochiral peptides to nanostructured and stable hydrogels in the case of heterochiral stereoisomers. Herein, we report that by further shortening the sequence to a dipeptide, the overall differences between isomers are less marked, with both homo- and hetero-chiral dipeptides forming gels, although with different stability over time. The soft materials are studied by a number of spectroscopic and microcopic techniques, and single-crystal X-ray diffraction to unveil the supramolecular interactions of these hydrogel building blocks.
氨基酸的立体构型已被证明在生理条件下，未受保护的三肽自组装成水凝胶中起着关键作用。基于二苯丙氨酸基序的疏水性序列发生了显著变化，对于同手性肽，形成无定形聚集体，而对于异手性立体异构体，则形成纳米结构且稳定的水凝胶。在此，我们报告说，通过进一步将序列缩短为二肽，同手性和异手性二肽都形成凝胶，尽管随时间的稳定性不同，但异构体之间的总体差异不那么明显。通过多种光谱和微观技术以及单晶 X 射线衍射研究了这些软材料，以揭示这些水凝胶构建块的超分子相互作用。
