重组Hepcidin融合蛋白的氧化复性及活性鉴定

将诱导表达的His-hepcidin融合蛋白包涵体通过固定化金属离子配体亲和层析(IMAC)柱分离纯化后,在cys-teine/cystine氧化还原体系中氧化形成二硫键,稀释复性后用肠激酶将融合蛋白的his-tag切除。酶切后所得的Hepcidin经抑菌圈试验检验,对枯草芽孢杆菌等革兰氏阳性菌和部分革兰氏阴性菌具有抗菌活性。     

木素过氧化物酶的研究进展

木素过氧化物酶是一种能降解木素,由微生物分泌的胞外酶,广泛应用于生物制浆、纸浆的酶法漂白、有机污染物的降解和环境的生物修复等方面.介绍了木素过氧化物酶的来源、结构与性质、催化机理以及基因工程方面的研究成果,并对其可能带来的工业应用前景以及今后的研究方向进行了展望.     

Five New Guaiane Sesquiterpenes from the Endophytic Fungus Xylaria sp. YM 311647 of Azadirachta indica

Five new guaiane sesquiterpenes, 1 – 5 , were isolated from the culture broth of the endophytic fungus Xylaria sp. YM 311647, isolated from Azadirachta indica A. Juss . The structures of these compounds were elucidated on the basis of spectroscopic analyses, and their inhibitory activities against five pathogenic fungi were evaluated. All guaiane sesquiterpenes showed moderate or weak antifungal activities in a broth microdilution assay.     

LC-MS/MS determination of helicid in human plasma and its application in pharmacokinetic studies

Helicid is a traditional Chinese medicine used to treat headache and insomnia with definite effects. To facilitate pharmacokinetic studies of helicid in man, a sensitive and specific LC-MS/MS method for the quantitative detection of helicid in human plasma was developed and validated. The method involved the addition of bergeninum as the internal standard (IS), protein precipitation, HPLC separation, and quantification by MS/MS system using negative electrospray ionization in the multiple reaction monitoring mode (MRM). The precursor→product ion transitions were monitored at m/z 282.8→120.9 for helicid and m/z 326.9→192.2 for the IS, respectively. The lower limit of quantification (LLOQ) was 0.2 μg/L. The calibration curves for helicid was linear over a concentration range of 0.2-20 μg/L. The intra- and inter-batch analyses of QC samples at 0.4, 2, 20 μg/L indicated good precision (%R.S.D. between 2.69 and 5.47%) and accuracy (between 96.15 and 105.05%). The helicid was stable in human plasma stored at room temperature for at least 24h, 4°C for at least 24h, -20°C for at least 1 month, and for routine three freeze-thaw cycles. This accurate and specific assay provides a useful method for evaluating the pharmacokinetic profile of helicid in humans.     

Bioleaching of chalcopyrite concentrate by a moderately thermophilic culture in a stirred tank reactor

A mixed culture of moderately thermophilic microorganisms was enriched from acid mine drainage samples collected from several chalcopyrite mines in China. Such mixed culture can be used to effectively extract copper from chalcopyrite. Furthermore, after being adapted to gradually increased concentration of chalcopyrite concentrate, the tolerance of the mixed culture to chalcopyrite concentrate was brought up to 80 g/L. The effects of several leaching parameters on copper recovery in stirred tank reactor also had been investigated. The results of the investigation show that it was possible to achieve a copper extraction rate of 75% in 44 days at a pulp density of 8%. The leaching rate of chalcopyrite concentrate tended to increase with dissolved total iron concentration. At low pH ranges, more microscopic counts of microorganisms were found in the solution. Furthermore, the analysis of leached residues indicates that the passivation of chalcopyrite concentrate was mainly due to a mass of jarosite and PbSO(4) on the mineral surface, other than the elemental sulphur layer. The bacterial community composition was analyzed by using Amplified Ribosomal DNA Restriction Analysis. Two moderately thermophilic bacteria species were identified as Leptospirillum ferriphilum and Acidithiobacillus caldus with abundance of 67% and 33% in the bio-pulp, respectively.     

中国表珠甲螨属二新记录种记述（甲螨亚目：珠甲螨科）

记述表珠甲螨属Epidamaeus 2中国新记录种:变表珠甲螨Epidamaeus variabilis Fujikawa & Fujita,1985及蒙古表珠甲螨Epidamaeus mongolicus Bayartogtokh, 2000,并分别对两种做了重新描述。     

CTAB-PEG DNA Extraction from Fungi with High Contents of Polysaccharides

Polysaccharides influence concentration and purity of extracted DNA. Here we present rapid and efficient protocol for DNA extraction from samples rich in polysaccharides. The technique has been developed using cultures of Schizophyllum commune and involves a modification of known Cetyltrimethyl Ammonium Bromide (CTAB) protocol. To remove polysaccharides, Polyethylene Glycol (PEG) 8000 was added during DNA precipitation. Genomic DNA obtained with the CTAB-PEG method had high integrity, with average fragment size >30 kb, the concentration higher than 100 ng/μL, and the yield more than 30 μg/g. Presented technique is suitable for DNA extraction from fungi, bacteria, archaea or even mollusks with high polysaccharide content.     

水稻线粒体DNA雄性不育有关特异片段的克隆及序列分析

应用任意单引物聚合酶链反应技术,从水稻ＷＡ 型雄性不育系的线粒体ＤＮＡ 中得到一个特异的扩增片段Ｒ２－６３０ ＷＡ。以该片段为探针进行Ｓｏｕｔｈｅｒｎ 杂交分析检测到在雄性不育胞质与正常可育胞质间存在的线粒体ＤＮＡ 多态性。不育系珍汕９７Ａ 和其Ｆ１ 杂种的杂交图谱相同。而保持系珍汕９７Ｂ和恢复系明恢６３ 的杂交图谱一样。序列测定该片段全长６２９ ｂｐ,其碱基组成Ａ＋ Ｔ＝ ５４．１％ ,同源性比较结果显示, 该片段与１２３６ 个已报道的植物基因（包括１６ 个水稻线粒体基因）序列的同源性均小于５０％ 。序列内含有一个长度为１０ ｂｐ 的反向重复序列５－ＡＣＣＡＴＡＴＧＧＴ－３,位于２６２—２７２ 区段。另外,其３７９—４３９ 区段可编码一个含２０个氨基酸残基的短肽。上述结果表明,Ｒ２－６３０ ＷＡ 片段确与水稻野败型雄性不育密切相关。推测反向重复序列５－ＡＣＣＡＴＡＴＧＧＴ－３在细胞质雄性不育性状形成中,可能起着重要作用     

The açaí flavonoid velutin is a potent anti-inflammatory agent: blockade of LPS-mediated TNF-α and IL-6 production through inhibiting NF-κB activation and MAPK pathway

Recent studies have shown that some flavonoids are modulators of proinflammatory cytokine production. In this study, velutin, a unique flavone isolated from the pulp of açaí fruit (Euterpe oleracea Mart.), was examined for its effects in reducing lipopolysaccharide-induced proinflammatory cytokine tumor necrosis factor (TNF)-α and interleukin (IL)-6 production in RAW 264.7 peripheral macrophages and mice peritoneal macrophages. Three other structurally similar and well-studied flavones, luteolin, apigenin and chrysoeriol, were included as controls and for comparative purposes. Velutin exhibited the greatest potency among all flavones in reducing TNF-α and IL-6 production. Velutin also showed the strongest inhibitory effect in nuclear factor (NF)-κB activation (as assessed by secreted alkaline phosphatase reporter assay) and exhibited the greatest effects in blocking the degradation of inhibitor of NF-κB as well as in inhibiting mitogen-activated protein kinase p38 and JNK phosphorylation; all of these are important signaling pathways involved in production of TNF-α and IL-6. The present study led to the discovery of a strong anti-inflammatory flavone, velutin. This compound effectively inhibited the expression of proinflammatory cytokines TNF-α and IL-6 in low micromole levels by inhibiting NF-κB activation and p38 and JNK phosphorylation.