Surfactant Protein SP-D, a member of the collectin family, is a pattern recognition protein, secreted by mucosal epithelial cells and has an important role in innate immunity against various pathogens. In this study, we confirm that native human SP-D and a recombinant fragment of human SP-D (rhSP-D) bind to gp120 of HIV-1 and significantly inhibit viral replication in vitro in a calcium and dose-dependent manner. We show, for the first time, that SP-D and rhSP-D act as potent inhibitors of HIV-1 entry in to target cells and block the interaction between CD4 and gp120 in a dose-dependent manner. The rhSP-D-mediated inhibition of viral replication was examined using three clinical isolates of HIV-1 and three target cells: Jurkat T cells, U937 monocytic cells and PBMCs. HIV-1 induced cytokine storm in the three target cells was significantly suppressed by rhSP-D. Phosphorylation of key kinases p38, Erk1/2 and AKT, which contribute to HIV-1 induced immune activation, was significantly reduced in vitro in the presence of rhSP-D. Notably, anti-HIV-1 activity of rhSP-D was retained in the presence of biological fluids such as cervico-vaginal lavage and seminal plasma. Our study illustrates the multi-faceted role of human SP-D against HIV-1 and potential of rhSP-D for immunotherapy to inhibit viral entry and immune activation in acute HIV infection. 相似文献
Peroxynitrite (ONOO−) has been vastly implicated in mutagenesis and cancer development. Present study probes the antigenicity of peroxynitrite damaged DNA (ONOO−-DNA) in cancer patients. Purified human placental DNA was damaged by the synergistic action of sodium nitroprusside (SNP) and Pyrogallol for 3 h at 37 °C. Binding characteristics of cancer autoantibodies as well as experimentally induced anti-peroxynitrite-DNA (anti-ONOO−-DNA) antibodies were assessed by ELISA and band shift assay. DNA modifications produced single strand breaks, decreased melting temperature (Tm), hyperchromicity in UV spectrum and decreased fluorescence intensity. The ONOO−-DNA induced high titre antibodies in experimental animals. Cancer autoantibodies exhibited enhanced binding with the modified DNA as compared to the native form. Lymphocyte DNA from cancer patients showed appreciable recognition of anti-ONOO−-DNA IgG as compared to the DNA from healthy subjects. The peroxynitrite modified DNA presents unique epitopes which may be one of the factors for the autoantibody induction in cancer patients. 相似文献
Sterol glycosyltransferases (SGTs) are ubiquitous but one of the most diverse group of enzymes of glycosyltransferases family. Members of this family modulate physical and chemical properties of secondary plant products important for various physiological processes. The role of SGTs has been demonstrated in the biosynthesis of pharmaceutically important molecules of medicinal plants like Withania somnifera.
Results
Analysis suggested conserved behaviour and high similarity in active sites of WsSGTs with other plant GTs. Substrate specificity of WsSGTs were analysed through docking performance of WsSGTs with different substrates (sterols and withanolides). Best docking results of WsSGTL1 in the form of stable enzyme-substrate complex having lowest binding energies were obtained with brassicasterol, transandrosteron and WsSGTL4 with solasodine, stigmasterol and 24-methylene cholesterol.
Conclusion
This study reveals topological characters and conserved nature of two SGTs from W. somnifera (WsSGTs) i.e. WsSGTL1 and WsSGTL4. However, besides being ubiquitous in nature and with broad substrate specificity, difference between WsSGTL1 and WsSGTL4 is briefly described by difference in stability (binding energy) of enzyme-substrate complexes through comparative docking.
Electronic supplementary material
The online version of this article (doi:10.1186/s12859-015-0563-7) contains supplementary material, which is available to authorized users. 相似文献
Parthenium poses serious threat to modern crop production system and
necessitate evaluating control practices for its effective management. Efficacy of
different weed control practices for controlling parthenium was explored in conventional and deep tillage systems in the field conditions. Hand hoeing (20 and
35 days after emergence), S-Metolachlor (pre-emergence herbicide), sorghum
straw mulch @ 5 tons ha-1 and combination of hand hoeing and sorghum straw
mulch (hand hoeing at 20 and straw mulch at 35 days after emergence) were used
as weed control practice. Weedy check where no weed control measure was
applied was also included in this experiment for comparison. Results concluded
that the all weed management treatments significantly reduced parthenium density, its fresh and dry biomass during both the years of study as compared to weedy check. Maximum sunflower achene yield was recorded in hand hoeing (20 and
35 days after emergence) in combination with deep tillage. So, mold bold plough
used for the purpose of deep tillage should be encouraged for better control of
parthenium and higher achene yield of sunflower crop (3293.3 kg ha-1 in 2017
and 3221.3 kg ha-1 in 2018). Moreover, is also inferred that total dose of herbicide
might be reduced by using hoeing and mulching in an integrated way. 相似文献
Summary Diurnal variations in water chemistry and plankton in this eutrophic tropical freshwater ponds were quite apparent. Large fluctuations were noted in dissolved oxygen, pH, carbonate and bicarbonate concentrations. The pond water gets oversaturated with oxygen during day (24.2 p.p.m.) and depleted in the night (1.2 p.p.m.). Diurnal migrations of plankton were not in conformity with temperate waters. 相似文献
Two chromium-resistant bacterial strains, Bacillus cereus S-6 and Ochrobactrum intermedium CrT-1, and two cyanobacterial strains, Oscillatoria sp. and Synechocystis sp., were used in this study. At initial chromate concentrations of 300 and 600 μg K2CrO4 mL−1, and an inoculum size of 9.6×107 cells mL−1, B. cereus S-6 completely reduced Cr(VI), while O. intermedium CrT-1 reduced Cr(VI) by 98% and 70%, respectively after 96 h. At 100 μg K2CrO4 mL−1, Synechocystis sp. MK(S) and Oscillatoria sp. BJ2 reduced 62.1% and 39.9% of Cr(VI), respectively, at 30°C and pH 8. Application of hexavalent chromate salts adversely affected wheat seedling growth and anatomical characters. However, bacterial inoculation alleviated the toxic effects, as reflected by significant improvements in growth as well as anatomical parameters. Cyanobacterial strains also led to some enhancement of various growth parameters in wheat seedlings.
This study investigated the adsorption potential of oil palm shell-based activated carbon to remove 2,4,6-trichlorophenol from aqueous solution using fixed-bed adsorption column. The effects of 2,4,6-trichlorophenol inlet concentration, feed flow rate and activated carbon bed height on the breakthrough characteristics of the adsorption system were determined. The regeneration efficiency of the oil palm shell-based activated carbon was evaluated using ethanol desorption technique. Through ethanol desorption, 96.25% of the adsorption sites could be recovered from the regenerated activated carbon. 相似文献
Gastrointestinal malignancies account for about 20% of all cancers worldwide. It is widely accepted that cancer evolves through several stepwise morphological stages such as the adenoma-carcinoma and hyperplastic polyp-serrated adenoma-carcinoma sequences in colorectal cancers, and the metaplasia-dysplasia-carcinoma sequences in esophageal and gastric cancers. The morphological progression is associated with the accumulation of multiple genetic and epigenetic events. It is now recognized that epigenetic silencing of gene expression by CpG island methylation is an important alternative mechanism of inactivating tumor suppressor genes. Inflammatory conditions of the gastrointestinal and pancreaticobiliary tracts and liver such as Barrett esophagus, Helicobacter pylori gastritis, inflammatory bowel disease and viral hepatitis, are associated with increased frequency of malignancies and CpG methylation. In addition, CpG methylation is present in aberrant crypt foci and pancreatic intraepithelial neoplasia that are considered putative precursors of colon and pancreatic carcinomas, respectively. Understanding of these early genetic and epigenetic changes allows for the discoveries of potential screening, monitoring and therapeutic strategies. Targeting of the epigenetic changes that occur before the development of frank malignancy offers a potential chemopreventive strategy. 相似文献
International Microbiology - Infections caused by Candida albicans are rising due to increment in drug resistance and a limited arsenal of conventional antifungal drugs. Thus, elucidating the novel... 相似文献
NAD glycohydrolases (NADases) catalyze the hydrolysis of NAD to ADP-ribose and nicotinamide. Although many members of the NADase family, including ADP-ribosyltransferases, have been cloned and characterized, the structure and function of NADases with pure hydrolytic activity remain to be elucidated. Here, we report the structural and functional characterization of a novel NADase from rabbit reticulocytes. The novel NADase is a glycosylated, glycosylphosphatidylinositol-anchored cell surface protein exclusively expressed in reticulocytes. shRNA-mediated knockdown of the NADase in bone marrow cells resulted in a reduction of erythroid colony formation and an increase in NAD level. Furthermore, treatment of bone marrow cells with NAD, nicotinamide, or nicotinamide riboside, which induce an increase in NAD content, resulted in a significant decrease in erythroid progenitors. These results indicate that the novel NADase may play a critical role in regulating erythropoiesis of hematopoietic stem cells by modulating intracellular NAD. 相似文献