NaCl提取浓度对猴头菌糖蛋白结构和免疫活性的影响OA

Five concentrations of NaCl(0.3,0.6,0.9,1.2,1.5 mol·L-1)were used to extract glycoproteins from Hericium erinaceus(designated as Ⅰ,Ⅱ,Ⅲ,Ⅳ,and Ⅴ,respectively).The resultant glycoproteins Ⅰ,Ⅱ,Ⅲ,Ⅳ,andⅤ were compared for polysaccharide content,protein content,structural characteristics(proportions of different secondary protein structures,monosaccharide composition,amino acid composition),as well as in vitro antioxidant activity and immunological activity.The correlations between NaCl concentration and these parameters were also analyzed.The results showed that the polysaccharide and protein contents of the five kinds of H.erinaceus glycoproteins were 5.55％-8.15％and 40.46％-75.96％,respectively.Glycoprotein Ⅲ had the highest polysaccharide content(8.15％),while glycoprotein Ⅱ had the highest protein content(75.96％).The secondary structures of all five glycoproteins were predominantly composed of β-sheets and random coils.Regarding monosaccharide composition,glycoproteins Ⅰ,Ⅱ,and Ⅲ were mainly composed of glucose and mannose,whereas glycoproteins Ⅳ and Ⅴ primarily contained glucose and galactose.Compared with Ⅳ and Ⅴ,glycoproteins Ⅰ,Ⅱ and Ⅲ contained higher levels of basic amino acids,acidic amino acids and essential amino acids.Glycoproteins Ⅰ,Ⅱ,and Ⅲ showed superior DPPH and ABTS radical scavenging abilities compared with Ⅳ and Ⅴ.All five glycoproteins stimulated the release of NO,TNF-α,and IL-6 from RAW264.7 macrophages.Compared with Ⅲ-Ⅴ,glycoproteins Ⅰ and Ⅱ exhibited better immunostimulatory activity.NaCl extraction concentration was negatively correlated with protein content,amino acid content,α-helix proportion,β-turn proportion,and total uronic acid content,while it was positively correlated with polysaccharide content,β-sheet proportion,and random coil proportion.