Download MendeleyGlycopeptide Self-Assembly Modulated by Glycan Stereochemistry through Glycan-Aromatic Interactions.
He, C., Wu, S., Liu, D., Chi, C., Zhang, W., Ma, M., Lai, L., Dong, S.(2020) J Am Chem Soc 142: 17015-17023
- PubMed: 32946227
- DOI: https://doi.org/10.1021/jacs.0c06360
- Primary Citation of Related Structures:
7C0N - PubMed Abstract:
Carbohydrates are often utilized to provide hydrophilicity and hydroxyl-based hydrogen bonds in self-assembling glycopeptides, affording versatile scaffolds with wide applicability in biomedical research. However, how stereochemistry of carbohydrates impacts the self-assembly process remains unclear. Here we have established a dimeric tyrosine-rich glycopeptide system for probing the corresponding hydrogelating behavior under the influence of site- and stereospecific glycosylations. Comparison of 18 glycoforms bearing monosaccharides at Tyr 4 and Tyr 4' shows that the glycopeptides with either α- or β-anomers exhibit contrary gelating abilities, when the glycan moieties contain axial hydroxyl groups. A high-resolution X-ray crystallographic structure of the β-galactose-containing gelator, along with other results from spectroscopic, microscopic, and rheological experiments, indicate an unusual carbohydrate-aromatic CH-π bonding that promotes glycopeptide self-assembly. These mechanistic findings, particularly evidence obtained at the angstrom scale, illuminate an unconventional role that carbohydrates can play in building supramolecules. Potential biomaterials exploiting the CH-π bond-based stabilization, as exemplified by an enzyme-resistant hydrogel, may thus be developed.
