Characterizing Heparin Tetrasaccharides Binding to Amyloid-Beta Peptide

The aggregation of beta-amyloid peptide (A beta) is one potential cause for Alzheimer's disease (AD). Heparin can either promote or inhibit A beta aggregation. The sulfation pattern and chain size determine its binding affinity and its role. Using 2D-NMR analysis and molecular modelling, the binding motif of heparin oligoaccharides to A beta was determined to be HexA-GlcNS-IdoA2S-GlcNS6S. Iduronic acid epimerization and 6-O-sulfation are key factors for the binding affinity, while 3-O-sulfation of Arixtra (heparin pentasaccharide) is not involved in the binding to A beta. Hydrogen-deuterium exchange mass spectrometry (HDX-MS) was used to study the glycosaminoglycan (GAG)-peptide complex and identified V12HHQKL17 as the binding site of GAG at A beta. Furthermore, an MTT assay was applied to evaluate the anti-A beta fibril formation function of heparin tetrasaccharide, and indicated that the heparin tetrasaccharide with the defined sequence represents a promising inhibitor of A beta aggregation.

Automated summary

The aggregation of beta-amyloid peptide (Aβ) is one potential cause for Alzheimer's disease, and heparin can either promote or inhibit Aβ aggregation. The sulfation pattern and chain size of heparin determine its binding affinity to Aβ. By studying the glycosaminoglycan (GAG)-peptide complex and conducting an MTT assay, it was found that heparin oligosaccharides with defined sequences represent promising inhibitors of Aβ aggregation.