Unravelling structure–function interactions between fluorinated heparan sulfate mimetics and signaling proteins†

Abstract

Fluorinated carbohydrates are emerging scaffolds in glycobiology, enabling the elucidation of the roles of the individual hydroxyl groups of a carbohydrate in protein binding and drug discovery. Herein, we report a divergent strategy to synthesize seven heparan sulfate (HS) mimetics featuring a fluorine atom at the C3 position of the glucuronic acid residue, with the objective of modulating structure–function relationships. The sensitivity of fluorine signals to sulfation patterns was confirmed via¹⁹F-NMR spectroscopy, while ³J_HH coupling and NOE data demonstrated that the glucuronic acid residue retained its ⁴C₁ conformation. Glycan microarray analysis and SPR binding studies revealed that a single hydroxyl-to-fluorine substitution in HS mimetics retains the binding of N-acetylated HS sequences for several growth factors and chemokines. Remarkably, GlcNAc6S-GlcA(3F) and GlcNS6S3S-GlcA(3F) exhibited binding properties comparable to those of highly N-sulfated native HS ligands. These findings provide valuable insights for the development of novel therapeutic agents targeting morphogens and cell signalling pathways.