Studies On The Interaction Between Pleurotus Ostreatus And White Mushroom Alkaline Extraction Polysaccharides And Galectin-1

Galectin-1 is a typical prototype galectin with a structurally conserved carbohydrate recognition domain(CRD)that specifically recognizes galactosidase,and it can reversibly bind to ligands containing galactosidase.Galacterin-1 forms dimers through hydrophobic interactions between monomers in aqueous solution and performs its biological functions in the form of dimers.The galectin plays an important role in cell development,apoptosis,adhesion and other physiological processes.In addition,it is closely related to the occurrence and development of tumors,which has a strong influence on the physiological processes of the formation,metastasis and immune escape of various tumors.Experiments have shown that certain polysaccharides are natural inhibitors of galectin,which produce immunomodulatory,anti-tumor,anti-aging and anti-oxidation activities through the action of galectin.The fungal polysaccharides have a wide range of sources,small toxic and side effects,and diverse activities,attracting increasing attention.This article isolated and purified two fungus neutral sugars,and then used red blood cell agglutination inhibition experiments to study the interaction between two sugars and galectin-1.The research contents and results are as follows:First,the galectin-1 and pET 28 a plasmids were recombined by means of molecular biology to construct a prokaryotic expression vector for galectin-1.The recombinant plasmid was transformed into E.coli expression system to induce gene expression so that the galectin-1 protein was isolated and purified.The use of chicken red blood cell agglutination test to detect the activity of galectin-1 showed that the prepared galectin-1 can agglutinate chicken red blood cells with a minimum agglutination concentration of 0.6 ?g/mL.Galectin-1 crystals were successfully collected in 40%(v/v)polyethylene glycol 3500(PEG3500)+ 0.1 M LiCl.X-ray diffraction gave a crystal structure called galectin-1 with a resolution of 3.17.Dilute alkali was used to extract Pleurotus ostreatus and polysaccharides of white mullet.The total polysaccharides APOP and AHMP of Pleurotus ostreatus and Pleurotus ostreatus were obtained,and the yields were 1.67% and 1.41%,respectively.Separation of total polysaccharides using DEAE-cellulose ion exchange chromatography yields two neutral sugar fractions,APOP-N and AHMP-N.The monosaccharide composition of APOP-N by HPLC was Man:Glc:Gal:Me-Gal:Fuc=13.8:60.6:19.4:4.7:2.1,and the monosaccharide composition of AHPMP-N was Man:Glc:Gal:Fuc= 12.3:34.2:40.7:12.8.The APOP-N and AHMP-N fractions were detected by using a galectin-1 induced red blood cell agglutination inhibition test.The experimental results show that APOP-N of Pleurotus ostreatus can hardly inhibit the agglutination of chicken erythrocytes by galectin-1,while the white waxy mushroom AHMP-N could inhibit the agglutination of red blood cells at a lower concentration,and the minimum inhibitory concentration was 0.15 mg/mL.Therefore,AHMP-N may be a better galectin-1 ligand.The results provide a theoretical basis and guidance for the development of fungi.