Diacetylene-Functionalized Glycan Mimetics for Receptor-Mediated Cluster Imprinting in Model Membranes

Abstract

The glycocalyx, a dense layer of glycoproteins and glycolipids on eukaryotic cells, is essential for cellular functions such as communication, signaling, and pathogen interactions. Certain components spontaneously organize into membrane microdomains, enhancing glycan-lectin interactions by clustering glycoproteins and glycolipids. However, studying these dynamic systems in native membranes is difficult due to their high heterogeneity. Synthetic glycocalyx mimetics have thus become valuable tools to replicate such complex interactions. In this study, we present diacetylene-containing multivalent glycomimetic ligands for integration into giant unilamellar vesicles as model membranes. We demonstrate the synthesis and application of a novel SPPoS-compatible building block that enables site-selective incorporation of a diacetylene moiety into sequence-defined, lipidated glycan mimetics. When incorporated into GUVs, the glycomimetic ligands cluster upon lectin binding, bringing diacetylene units into close proximity. UV irradiation then induces polymerization, yielding fluorescent polydiacetylene clusters that mimic receptor-mediated glycan clustering in cell membranes. This approach allows precise control over glycan cluster formation and provides a versatile platform for studying multivalent glycan-lectin interactions in clustering and membrane microdomain organization. By stabilizing glycan clusters, this system offers valuable potential for advancing our understanding of membrane-associated glycan interactions and their role in cellular signaling.

Keywords: aggregation; clustering; glycocalyx; glycoconjugates; lectin; polydiacetylenes; polymers; vesicles.