| Lentinan,a triple-helical β-1,3-D-glucan isolated from lentinus edodes,is clinically used as an immune enhancement drug for tumor therapy.Dectin-1 is a cell-surface immune receptor for β-glucans,which plays an important role in immunological defense against fungal pathogens and β-glucan-mediated immune modulation.However,the advanced structure of lentinan and how dectin-1 is involved in lentinan’s pharmacological activity is not completely certain.This study applied water extraction-alcohol precipitation method and then decolorization,ultrafiltration and lyophilization to obtain the refined lentinan as the substance basis for the latter experiments.In this study,the emerging molecular dynamics(MD)simulation technique was applied to investigate and predict the conformation of lentinan in water,including some properties such as hydrogen bonds,dihedral angles,side-chain orientation.Surface plasmon resonance(SPR)and Fluorescence spectroscopy(FS)were adopted to verify the binding of lentinan with dectin-1.Through macromolecular docking and MD simulation,we simulated the detailed mechanism of lentinan’s binding to dectin-1.We found that lentinan could maintain its triple-helix worm-like shaped structure in water,for which hydrogen bonds serving as the driving force.SPR assay proved lentinan could bind to dectin-1,and FS experiment speculated that the binding of lentinan to dectin-1 might trigger the conformational change of dectin-1.Via computational simulation,the results showed that the formation of hydrogen bonds and CH-π interaction were the major contributions to the recognition process,and a loop-domain of the protein went through a conformational change.Our work deeply studied the advanced structure of lentinan and the recognition of β-glucan lentinan for dectin-1 receptor,which has set a good basis and foundation for future studies. |
