Synthesis of BODIPY-Labeled Cholesterylated Glycopeptides by Tandem Click Chemistry for Glycocalyxification of Giant Unilamellar Vesicles (GUVs)

5 years ago

Synthesis of BODIPY-Labeled Cholesterylated Glycopeptides by Tandem Click Chemistry for Glycocalyxification of Giant Unilamellar Vesicles (GUVs)

Nicolai Stuhr-Hansen, Charikleia-Despoina Vagianou, Ola Blixt

The glycocalyx cover membrane surfaces of all living cells. These complex architectures render their interaction mechanisms on the membrane surface difficult to study. Artificial cell-sized membranes with selected and defined glycosylation patterns may serve as a minimalistic approach to systematically study cell surface glycan interactions. The development of a facile general synthetic procedure for the synthesis of BODIPY-labeled cholesterylated glycopeptides, which can coat cell-size giant unilamellar vesicles (GUVs), is described. These peptide constructs were synthesized by: 1) solid-phase peptide synthesis (SPPS) using cholesterylated Fmoc-amino acids (Fmoc=9-fluorenylmethoxycarbonyl) followed by tandem click reactions, 2) attachment of a BODIPY-bicyclononyne (BCN) (prepared by Mitsunobu chemistry via novel aryl BCN-ethers) in the absence of a catalyst, and 3) glycosylation by means of copper(I)-catalyzed click reaction of an azidoglycan. Seven different GUV-glycoforms were prepared and four of these were evaluated with their corresponding four specific anti-glycan binding lectins. Double functionalization of cholesterylated peptide constructs by site-specific tandem click chemistry is described. Copper-free click attachment of a bicyclononyne fluorophore succeeded by copper(I)-catalyzed clicking on an azido-glycan.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201702104