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991.
Duan Z Yan X Cao R Liu Z Wang X Liang S 《Journal of biochemical and molecular toxicology》2008,22(5):328-336
Black widow spider is one of the most poisonous spiders in the world. Up to now, there have been few systematic analyses of the spider venom components, and the mechanism of action of the venom has not been completely understood. In this work, we employed combinative proteomic strategy to analyze the venom collected from living adult spider Latrodectus tredecimguttatus by electrical stimulation. The experiments demonstrated that the venom is primarily composed of high molecular weight proteins and has high abundance proteins around 100 kDa. The content of peptides and proteins with low molecular weight is low. A total of 75 nonredundant venom proteins with distinct function were unambiguously identified. Besides the known black widow spider venom proteins including latrotoxins, a variety of hydrolases and other proteins with special activity were found in the venom, such as proteinase, phospholipase, phosphatase, nuclease, fucolectin, venom allergen antigen 5-like protein and trypsin inhibitor, and so on. Their possible biological actions and relationship with latrodectism were discussed. The results help to understand the complexity and action mechanism of L. tredecimguttatus venom. 相似文献
992.
Treatment of H2S using a horizontal biotrickling filter based on biological activated carbon: reactor setup and performance evaluation 总被引:1,自引:0,他引:1
Biological treatment is an emerging and prevalent technology for treating off-gases from wastewater treatment plants. The most commonly reported odorous compound in off-gases is hydrogen sulfide (H2S), which has a very low odor threshold. A self-designed, bench-scale, cross-flow horizontal biotrickling filter (HBF) operated with bacteria immobilized activated carbon (termed biological activated carbon—BAC), was applied for the treatment of H2S. A mixed culture of sulfide-oxidizing bacteria dominated by Acidithiobacillus thiooxidans acclimated from activated sludge was used as bacterial seed and the biofilm was developed by culturing the bacteria in the presence of carbon pellets in mineral medium. HBF performance was evaluated systematically over 120 days, depending on a series of changing factors including inlet H2S concentration, gas retention time (GRT), pH of recirculation solution, upset and recovery, sulfate accumulation, pressure drop, gas-liquid ratio, and shock loading. The biotrickling filter system can operate at high efficiency from the first day of operation. At a volumetric loading of 900 m3 m–3 h–1 (at 92 ppmv H2S inlet concentration), the BAC exhibited maximum elimination capacity (113 g H2S/m–3 h–1) and a removal efficiency of 96% was observed. If the inlet concentration was kept at around 20 ppmv, high H2S removal (over 98%) was achieved at a GRT of 4 s, a value comparable with those currently reported for biotrickling filters. The bacterial population in the acidic biofilter demonstrated capacity for removal of H2S over a broad pH range (pH 1–7). A preliminary investigation into the different effects of bacterial biodegradation and carbon adsorption on system performance was also conducted. This study shows the HBF to be a feasible and economic alternative to physical and chemical treatments for the removal of H2S. 相似文献
993.
模拟氮沉降对温带典型森林土壤有效氮形态和含量的影响* 总被引:2,自引:0,他引:2
通过室内模拟氮沉降试验,研究了氮沉降对温带典型森林土壤有效氮的影响.结果表明:试验期间,与对照相比,经过氮沉降处理的土壤铵态氮、硝态氮和有效氮均呈增长的趋势,增加的程度取决于森林类型、土层、氮处理类型和氮处理的持续时间.氮沉降对不同林型土壤有效氮形态和含量的影响不同,氮沉降对混交林的影响弱于阔叶林,强于针叶人工纯林;土壤A层对氮沉降的敏感程度大于土壤B层;铵态氮形态沉降对土壤铵态氮含量的影响比对土壤硝态氮含量的影响大,而硝态氮形态沉降对土壤硝态氮含量的影响比对土壤铵态氮含量的影响大,混合形态的氮沉降对二者均有促进作用,且增加幅度更高;氮沉降对土壤有效氮的影响存在累加效应. 相似文献
994.
995.
已被发现和命名的白介素有19种,其相应的受体大多也已被克隆及鉴定。白介素及其受体的结构特征决定了其信号转导和功能效应的共性和特性。许多白介素及可溶性受体在临床疾病的治疗中可能起重要作用,同时这也带动了对白介素及其受体的基因工程研究。随着基因组计划的日趋完成和一些新的分子生物学技术方法的建立,对白介素及其受体的研究在许多方面都面临着新的机遇和挑战。 相似文献
996.
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998.
Hepatitis B virus (HBV) core protein (HBc) is a major component of viral nucleocapsid and a multifunctional protein involved
in viral maturation and release. It is unstable and present in cells at low level because of K96 lysine residue, which is
a ubiquitin acceptor site. Np95/ICBP90-like RING finger protein (NIRF) has auto-ubiquitination activity which is the hallmark
of a ubiquitin ligase. In the present study, ubiquitin ligase, NIRF, binds to HBc and leads to the proteasome-mediated degradation
of HBc in vivo. NIRF down-regulates HBc protein level, resulting in the decrease of the amount of HBV particles in supernatant
of HepG2.2.15 cells. However knockdown of NIRF significantly increases endogenous HBc protein level, leading to HBV release.
The results reveal that NIRF interacts with HBc and promotes the degradation of HBc in vivo. The pathway of NIRF-mediated
ubiquitin–proteasome affects the release of HBV particles by controlling the amounts of HBc. It indicates that NIRF may participate
in the maturation of HBV. 相似文献
999.