Comparative Studies On The Interaction Between RG-I Pectin And Galectin-1,-2,-3,-8

Galectins can bind to carbohydrates on the cell membrane and on the extracellular matrix.Its function varies depending on the structure of different galectins.Galectin-1,-2,-3 and-8 all play a role in the development of tumors,and participate in the recognition and adhesion between tumor cells and cells or periplasm,affecting tumor proliferation and migration.Galectin-1,-2,-3 and-8 can be used as drug targets for a variety of cancer treatments,therefore the development of their inhibitors is of great significance for the treatment of cancer.Studies have shown that RG-I pectin has a high affinity with galectin-3,but the interaction between RG-I pectin and other galectins has rarely been reported.Therefore,in this thesis,ginseng RGI pectin and potato RG-I pectin with different structures were prepared,and their interaction with galectin-1,-2,-3 and-8 was detected,aiming to explore their interaction regularity.First of all,ginseng RG-I pectin 2A-UDp was prepared chromatography and enzymatic hydrolysis.Potato RG-I pectin GPS-A,GPS-B and GPS-Cp with different proportion of side chain galactan was obtained by gel column chromatography.Then galectin-1,-2,-3 and-8 with high concentration was extracted and purified.Finally,the interaction between RG-I type pectin with different structures and galectin-1,-2,-3 and-8 was detected by hemagglutination inhibition assay and bio-layer interferometry method,and the regularity was summarized.Hemagglutination inhibition experiments showed that there was interaction between RG-I pectin and galectin-1,-3 and-8,and the increase of side chain galactan content enhanced the inhibition of hemagglutination induced by galectin-1,-3,and-8.Bio-layer interference experiments showed that there was no affinity between galectin-2 and RG-I pectin,and the binding between galectin-1 and RG-I pectin was relatively weak.There was a high affinity between galectin-3,galectin-8 and RG-I pectin.The molecular weight increase of RG-I pectin weakened the binding between galectin-3,galectin-8 and RG-I pectin to some extent,and made the interaction between RG-I pectin and galectin-1 disappeared.It is speculated that under the condition of "liquid phase-solid phase" reaction,when the molecular weight of RG-I pectin got larger,the steric hindrance would hinder the binding between pectin and galectin,therefore the increase in the amount of side chain galactan of the RG-I pectin did not show an enhanced effect on the interaction.In this paper,RG-I pectins with different structures were prepared and analyzed,which will enrich the basis research of polysaccharide structure.In addition,the study on the interaction between RG-I pectin and galectins will provide new information for the development and application of galectin inhibitors and polysaccharide anti-tumor drugs.