Grajda M, Lewińska M J, Szumna A
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-22 Warsaw, Poland.
Org Biomol Chem. 2017 Oct 18;15(40):8513-8517. doi: 10.1039/c7ob01925d.
Peptide-based cavitands (resorcin[4]arenes substituted with histidine and glutamine hydrazides) exist as monomeric species in polar solvents (DMSO and methanol). Upon complexation of fullerenes, the cavitands wrap around the hydrophobic guests forming dimeric capsular shells (as evidenced by DOSY). The self-assembly of the cavitands is based on the formation of beta-sheet-like binding motifs around the hydrophobic core. In a polar environment, these hydrogen bonded structures are kinetically stable and highly ordered as manifested by a 100-fold increase of intensity of circular dichroism bands, as well as a separate set of signals and substantial differences in chemical shifts in NMR spectra. This behavior resembles a protein folding process at the molten globule stage with non-specific hydrophobic interactions creating a protective and favourable local environment for the formation of secondary structures of proteins.
基于肽的穴状配体（用组氨酸和谷氨酰胺酰肼取代的间苯二酚[4]芳烃）在极性溶剂（二甲基亚砜和甲醇）中以单体形式存在。在与富勒烯络合时，穴状配体围绕疏水客体包裹形成二聚体囊状壳层（扩散排序光谱法证明）。穴状配体的自组装基于围绕疏水核心形成β-折叠样结合基序。在极性环境中，这些氢键结构在动力学上是稳定且高度有序的，这表现为圆二色性带强度增加100倍，以及核磁共振光谱中有一组单独的信号和化学位移的显著差异。这种行为类似于蛋白质在熔球阶段的折叠过程，非特异性疏水相互作用为蛋白质二级结构的形成创造了一个保护性的有利局部环境。
