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Publication Abstract from PubMed

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 alpha- or beta-anomers exhibit contrary gelating abilities, when the glycan moieties contain axial hydroxyl groups. A high-resolution X-ray crystallographic structure of the beta-galactose-containing gelator, along with other results from spectroscopic, microscopic, and rheological experiments, indicate an unusual carbohydrate-aromatic CH-pi 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-pi bond-based stabilization, as exemplified by an enzyme-resistant hydrogel, may thus be developed.

Glycopeptide 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 J Am Chem Soc. 2020 Sep 25. doi: 10.1021/jacs.0c06360. PMID:32946227^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.