12. Glycopeptide Self-Assembly Modulated by Glycan Stereochemistry through Glycan−Aromatic Interactions
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作者: Changdong He, Shuang Wu, Dangliang Liu, Changbiao Chi, Weilin Zhang, Ming Ma, Luhua Lai, and Suwei Dong*
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发布时间: 2020-11-20
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J. Am. Chem. Soc. 2020, 142, 40, 17015–17023
Changdong He, Shuang Wu, Dangliang Liu, Changbiao Chi, Weilin Zhang, Ming Ma, Luhua Lai, and Suwei Dong*
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 Tyr4 and Tyr4′ 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.
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