Different molecular sizes and chain conformations of water-soluble yeast β-glucan fractions and their interactions with receptor Dectin-1

Although beta-glucan could bind to Dectin-1 to exert bioactivity, the influence of molecular size and chain conformation of beta-glucan on its interaction with Dectin-1 is still unclear. This work investigated the molecular sizes and chain conformations of five water-soluble yeast beta-glucan (WYG1-5) fractions as well as their interactions with Dectin-1 by fluorescence spectroscopy and microscale thermophoresis. Results revealed a spherical conformation for higher molecular weight WYG and a stiff chain conformation for smaller molecular weight WYG. The WYG and Dectin-1 interactions were in the order of WYG-2 > WYG-1 > WYG-3 > WYG-4 > WYG-5. The spherical WYG-2 exhibited the largest binding constant of 7.91 x 10(5) M-1 and the lowest dissociation constant of 22.1 nM to Dectin-1. Additionally, the underlying interaction mechanism showed that it may be easier for spherical WYG with longer side chains to interact with receptor Dectin-1.

Automated summary

The study investigated the influence of molecular size and chain conformation of water-soluble yeast beta-glucan on its interaction with Dectin-1, revealing that higher molecular weight beta-glucan exhibited a spherical conformation while smaller molecular weight beta-glucan showed a stiff chain conformation. The interaction between beta-glucan and Dectin-1 was found to be easier for spherical beta-glucan with longer side chains.