2 research outputs found
Tailored Presentation of Carbohydrates on a Coiled Coil-Based Scaffold for Asialoglycoprotein Receptor Targeting
The
coiled-coil folding motif represents an ideal scaffold for the defined
presentation of ligands due to the possibility of positioning them
at specific distances along the axis. We created a coiled-coil glycopeptide
library to characterize the distances between the carbohydrate-binding
sites of the asialoglycoprotein receptors (ASGPR) on hepatocytes.
The components of the glycopeptide library vary for the number of
displayed ligands (galactose), their position on the peptide sequence,
and the space between peptide backbone and carbohydrate. We determined
the binding of the glycopeptides to the hepatocytes, and we established
the optimal distance and orientation of the galactose moieties for
interaction with the ASGPR using flow cytometry. We confirmed that
the binding occurs through endocytosis mediated by ASGPR <i>via</i> inhibition studies with cytochalasin D; fluorescence microscopy
studies display the uptake of the carrier peptides inside the cell.
Thus, this study demonstrates that the coiled-coil motif can be used
as reliable scaffold for the rational presentation of ligands
Analysis of Carbohydrate–Carbohydrate Interactions Using Sugar-Functionalized Silicon Nanoparticles for Cell Imaging
Protein-carbohydrate binding depends
on multivalent ligand display that is even more important for low
affinity carbohydrate–carbohydrate interactions. Detection
and analysis of these low affinity multivalent binding events are
technically challenging. We describe the synthesis of dual-fluorescent
sugar-capped silicon nanoparticles that proved to be an attractive
tool for the analysis of low affinity interactions. These ultrasmall
NPs with sizes of around 4 nm can be used for NMR quantification of
coupled sugars. The silicon nanoparticles are employed to measure
the interaction between the cancer-associated glycosphingolipids GM3
and Gg3 and the associated <i>k</i><sub>D</sub> value by
surface plasmon resonance experiments. Cell binding studies, to investigate
the biological relevance of these carbohydrate–carbohydrate
interactions, also benefit from these fluorescent sugar-capped nanoparticles