Effect of galactose side-chain on the self-assembly of xyloglucan macromolecule

As a common side-chain residue of polysaccharide, galactose plays a significant role in multiple aspects of the macromolecules. This study showed how degalactosylation induced drastic self-assembly transition of xyloglucan from spherical aggregates toward ribbon-like aggregates, and how it led to largely decreased water solubility and apparent viscosity within a short range of galactose removal ratio. To better understand this phenomenon, the size of the ellipsoid-like aggregated nanoparticles were carefully measured and compared, and it was found out that those nanoparticles which lost more galactose residues turned out to be more slender and tend to bind and stack closely in parallel, thereby forming huge ribbon-like aggregates. The galactose residue is considered as the hydrophilic group, and the decreased number of which caused a more hydrophobic behavior.