靶向Wnt/β-catenin信号通路抑制剂研究进展

Wnt/β-catenin信号通路高度复杂,与Notch通路、Hedgehog通路等都有密切联系,参与机体胚胎发育、调控生物体细胞增殖、代谢等多个方面.研究发现,该信号通路的异常激活与肿瘤密切相关.据汤森路透数据库统计发现,截至2014-04-24,共报道Wnt信号通路抑制剂228个,主要分为受体抑制剂和胞内小分子抑制剂等.本文综述了Wnt/β-catenin信号通路抑制剂及其调控机制,旨在为肿瘤预防与治疗提供新素材.     

Inhibitive effect of Xylopia ferruginea extract on the corrosion of mild steel in 1M HCl medium

The alkaloid content of the leaves and stem bark of Xylopia ferruginea plant was isolated and tested for its anticorrosion potential on mild steel corrosion in a hydrochloric acid medium by using electrochemical impedance spectroscopy,potentiodynamic polarization measurement,scanning electron microscopy(SEM),and Fourier transform infra red(FTIR) analysis.The experimental results reveal the effective anticorrosion potential of the plant extract.The mixed mode of action exhibited by the plant extract is evidenced from the polarization study.SEM images proof the formation of a protective layer over the mild steel surface,and this is supported by the FTIR study.The possible mode of the corrosion inhibition mechanism has also been discussed.     

一种新的植物生长抑制剂生物活性鉴定法

报告一种新的植物生长抑制剂生物活性鉴定法一油菜（Ｂｒａｓｓｉｃａ ｃａｍｐｅｓｔｒｉｓＬ）下胚轴试法，该试法以浸渍法处理吸涨２ｈ的油菜种子，２６℃黑暗保温５３ｈ后测定结果，以１０μｇ／ｍｌ的检测浓度可将１０种已知抑制剂的活性准确多分开来。检测ＡＢＡ、Ｓ０７和Ｓ０８的线性浓度范围均为０．００１～１μｇ／ｍＬ，ＰＰ３３３为０．１～１μｇ／ｍＬ。它与某些经典试法的反应灵敏度相当或更高，且更加简便快速。     

Structural properties of matrix metalloproteinases

Matrix metalloproteinases (MMPs) are involved in extracellular matrix degradation. Their proteolytic activity must be precisely regulated by their endogenous protein inhibitors, the tissue inhibitors of metalloproteinases (TIMPs). Disruption of this balance results in serious diseases such as arthritis, tumour growth and metastasis. Knowledge of the tertiary structures of the proteins involved is crucial for understanding their functional properties and interference with associated dysfunctions. Within the last few years, several three-dimensional MMP and MMP-TIMP structures became available, showing the domain organization, polypeptide fold and main specificity determinants. Complexes of the catalytic MMP domains with various synthetic inhibitors enabled the structure-based design and improvement of high-affinity ligands, which might be elaborated into drugs. A multitude of reviews surveying work done on all aspects of MMPs have appeared in recent years, but none of them has focused on the three-dimensional structures. This review was written to close the gap. Received 18 November 1998; accepted 11 December 1998     

基于人芳香酶的雄甾烷衍生物抗乳腺癌构效关系研究

为研究以雄甾烷衍生物作为人芳香酶抑制剂的构效关系,以ZINC数据库中80%相似性的5045种类似结构化合物为配体,利用蛋白质晶体数据(3EQM)通过Sybyl软件中的SurFlex模块进行分子对接虚拟筛选并打分,得到分值在8.0分以上的25个化合物作为中靶化合物.     

含水原油的防蜡剂应用研究

介绍了一种大庆原油和一种胜利桩西原油使用水基型防蜡剂ＷＰＥ－Ｆ２的防蜡，降粘实验情况，讨论了原油中水的质量分数对防蜡剂作用效果的影响。     

Mast cell tryptase,a still enigmatic enzyme

Tryptases constitute a subfamily of trypsin-like proteinases, stored in the mast cell secretory granules of all mammalian organisms. These enzymes are released along with other mediators into the extracellular medium upon mast cell activation/degranulation. Among the trypsin-like enzymes, tryptases are unique: they are present as active enzymes in the mast cell granules, but display activity only extracellularly, and have a specificity which is much more restricted than trypsin. Tryptases are mostly tetrameric, and in only few organisms (not in humans) are they inhibited by endogenous inhibitors in vitro. The enzymatic and molecular properties of tryptases are far better characterized that any of their plausible biological functions. On the basis of its structural and functional features it could be predicted that tryptase would not degrade a large number of proteins in vivo due to low accessibility to the tetramer central pore where the active sites face inwards. Although their biological function has not yet been clarified, tryptases seem to be involved in a number of mast cell-mediated allergic and inflammatory diseases. In particular, the involvement of tryptase in asthma, an inflammatory disease of the airways often caused by allergy, has been proposed. Here we review the present knowledge on the structure-function relationship of tryptases from different organisms, with special emphasis on human enzymes, and on their role in a variety of pathophsyiological processes.Received 29 October 2003; received after revision 3 December 2003; accepted 11 December 2003     

Protein proteinase inhibitors from avian egg whites

Avian egg whites are a rich source of protein inhibitors of proteinases belonging to all four mechanistic classes. Ovomucoid and ovoinhibitor are multidomain Kazal-type inhibitors with each domain containing an actual or putative reactive site for a serine proteinase. Cystatin is a cysteine proteinase inhibitor, while ovostatin inhibits proteinases of all four mechanistic classes. In this review we have summarized the general features, isolation, inhibitory mechanism and evolutionary aspects of these inhibitors. Received 6 March 1996; received after revision 17 June 1996; accepted 10 July 1996     

几种新型苯甲酰基脲类化合物的杀虫活性研究

 以商品苯甲酰基脲类杀虫剂伏虫脲为参照,室内对比测定了6个新型苯甲酰基脲类化合物对四龄粘虫的毒杀活性及对蚊幼虫的毒杀活性.实验结果表明,化合物1a对四龄粘虫的毒杀活性与伏虫脲相当.伏虫脲1a～f的LC50值分别为:1.82,1.84,4.85,9.20,70.79,18.88,23.12.而对蚊幼虫的毒杀活性试验中,1a～b的活性显著高于伏虫脲.1a～f伏虫脲的LC50值分别为:0.00086,0.00175,0.00852,0.0160,0.00680,0.02270,0.00958.从以上结果可以得出结论:化合物1a～c具有较好的杀粘虫幼虫活性,而1a～b具有极佳的杀蚊幼虫活性.