OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crud...OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crude polysaccharides were obtained. After purification by DEAE-cellulose 52 ion exchange chromatography and Sephacryl S-300 HR gel filtration chromatography, High performance liquid chromatography equipped with evaporative light-scattering detector, Infrared radiation and Nuclear magnetic resonance were used to evaluate the structure of the polysaccharide. Its immunomodulatory activity was measured by examining the production of nitric oxide(NO) and cytokine secretion, and via lymphocyte proliferation experiments. Its effects on the scavenging activities of hydroxyl radical, superoxide anion and reducing power were also measured.RESULTS: A water-soluble polysaccharide, Flammulina velutipes polysaccharide I-A(FVP I-A), was obtained with a molecular mass of 8.14×104Da determined by high performance gel permeation chromatography. An in vitro antioxidant assay indicated that FVP I-A could scavenge hydroxyl radical, superoxide anion and possessed reducing power and could largely promote NO production and augment the interleukin-1β, interleukin-6, and tumor necrosis factor-α secretion by RAW264.7 macrophages(P<0.05). Moreover, FVP I-A could promote lymphocyte proliferation(P<0.05), and synergistically enhance the augmentation of the proliferation of mouse lymphocytes by concanavalin A and lipopolysaccharides(P<0.01, P<0.05).CONCLUSION: The FVP I-A obtained from Flammulina velutipes possessed antioxidant activity and could enhance non-specific and specific immune responses in vitro.展开更多
Our previous study demonstrated that WLIMla has dual roles in fiber elongation and secondary cell wall synthesis in upland cotton, and the protein acts either as an actin-binding protein or as a transcription factor. ...Our previous study demonstrated that WLIMla has dual roles in fiber elongation and secondary cell wall synthesis in upland cotton, and the protein acts either as an actin-binding protein or as a transcription factor. Because WLIMla consists of two different LIM domains, it is possible that these elements contribute differentially to the dual functions of the protein. In this study, we dissected the two LIM domains and characterized their biochemical functions. By using red fluorescent protein （RFP） fusion, co-sedimentation, and DNA binding methods, we found that the two domains of WLIM 1 a, domain 1 （D 1） and domain2 （D2）, possessed different biochemical properties. While D1 contributed primarily to the actin filament-bundling activity of WLIMla, D2 contributed to the DNA-binding activity of the protein; both D1 and D2 relied on a linker sequence for their ac- tivities. In addition, we found that WLIMla and its two LIM domains form dimers in vitro. These results may lead to a better understanding of the molecular mechanisms of dual functions of WLIMla during cotton fiber development.展开更多
基金the Fungus Medicine Research and Development-Innovation Team of Science and Technology in Sichuan Province,the Key Project of Deep Processing Research Positions Construction in Sichuan Province[No.Sichuan Agriculture(2009)75]Fungi Herbs Research and Development of Scientific and Technological Innovation in Sichuan Province Team,Second Five Breeding Research Project in Sichuan Province"Collection of Mushrooms Medicinal Quality Germplasm Resources and Breeding of New Materials"(No.2011nz0098-12-04)+2 种基金The Sichuan Province Microbial Resource Sharing Platform-Agricultural Microbiology Platform ProjectA Major Science And Technology Projects of Sichuan Province"Industrial Chain Integration of Key Technology Research and Industrialization Demonstration of Edibleand Medicinal Fungi Modern"The Project of Eight Technology Industries in Chengdu:the Key Technology Research and Application of Edible And Medicinal Mushroom With Deep Processing
文摘OBJECTIVE: To evaluate the antioxidant and immunomodulatory activities of a unique polysaccharide from the medicinal fungus Flammulina velutipes in vitro.METHODS: Using water extraction and alcohol precipitation, crude polysaccharides were obtained. After purification by DEAE-cellulose 52 ion exchange chromatography and Sephacryl S-300 HR gel filtration chromatography, High performance liquid chromatography equipped with evaporative light-scattering detector, Infrared radiation and Nuclear magnetic resonance were used to evaluate the structure of the polysaccharide. Its immunomodulatory activity was measured by examining the production of nitric oxide(NO) and cytokine secretion, and via lymphocyte proliferation experiments. Its effects on the scavenging activities of hydroxyl radical, superoxide anion and reducing power were also measured.RESULTS: A water-soluble polysaccharide, Flammulina velutipes polysaccharide I-A(FVP I-A), was obtained with a molecular mass of 8.14×104Da determined by high performance gel permeation chromatography. An in vitro antioxidant assay indicated that FVP I-A could scavenge hydroxyl radical, superoxide anion and possessed reducing power and could largely promote NO production and augment the interleukin-1β, interleukin-6, and tumor necrosis factor-α secretion by RAW264.7 macrophages(P<0.05). Moreover, FVP I-A could promote lymphocyte proliferation(P<0.05), and synergistically enhance the augmentation of the proliferation of mouse lymphocytes by concanavalin A and lipopolysaccharides(P<0.01, P<0.05).CONCLUSION: The FVP I-A obtained from Flammulina velutipes possessed antioxidant activity and could enhance non-specific and specific immune responses in vitro.
基金the National Basic Research Priorities Program (U1303281)the China Postdoctoral Science Foundation
文摘Our previous study demonstrated that WLIMla has dual roles in fiber elongation and secondary cell wall synthesis in upland cotton, and the protein acts either as an actin-binding protein or as a transcription factor. Because WLIMla consists of two different LIM domains, it is possible that these elements contribute differentially to the dual functions of the protein. In this study, we dissected the two LIM domains and characterized their biochemical functions. By using red fluorescent protein （RFP） fusion, co-sedimentation, and DNA binding methods, we found that the two domains of WLIM 1 a, domain 1 （D 1） and domain2 （D2）, possessed different biochemical properties. While D1 contributed primarily to the actin filament-bundling activity of WLIMla, D2 contributed to the DNA-binding activity of the protein; both D1 and D2 relied on a linker sequence for their ac- tivities. In addition, we found that WLIMla and its two LIM domains form dimers in vitro. These results may lead to a better understanding of the molecular mechanisms of dual functions of WLIMla during cotton fiber development.
