A fusion protein of conotoxin MVIIA and thioredoxin expressed in Escherichia coli has significant analgesic activity

omega-Conotoxin MVIIA (CTX MVIIA) is a potent and selective blocker of the N-type voltage-sensitive calcium channel in neurons. Its analgesic and neuroprotective effects may prove useful in treatment of severe pains and ischemia. In this paper, we report that a fusion form of CTX MVIIA with thioredoxin (Trx) has analgesic function. The DNA fragments were chemically synthesized and ligated to form the DNA sequence encoding CTX MVIIA. The synthetic gene was then cloned into the expression vector pET-32a(+) and the fusion protein Trx-CTX MVIIA containing 6x His-tag was purified by one-step metal chelated affinity chromatography (MCAC). The purity of final product was over 95% determined by HPLC and the yield of the fusion protein was approximately 40 mg/L. The analgesic function was detected by using mouse hot-plate assay. After intracranially administering fusion protein with the dose of 0.6 mg/kg, marked analgesia was observed. The analgesic effects (elevated pain thresholds) were dose-dependent and the biological half-life of the fusion toxin was approximately 1.6 h.     

Identification of metastasis-associated proteins by proteomic analysis and functional exploration of interleukin-18 in metastasis

Very little is currently known about mechanisms underlying cancer metastasis. In the present study, metastasis-associated proteomes were separated and identified by comparative proteomic analysis, and the metastasis-related function of candidate protein interleukin-18 (IL-18) was further elucidated. First, a pair of highly and poorly metastatic sublines (termed PLA801D and PLA801C, respectively), originating from the same parental PLA801 cell line, was identified by spontaneous tumorigenicity and metastasis in vivo and characterized by metastatic phenotypes analysis in vitro. Subsequently, a proteomic approach was used to compare the protein expression profiles between PLA801C and PLA801D sublines. Eleven proteins were identified and further verified by one-dimensional Western blotting, Northern blot and/or semiquantitative reverse transciptase polymerase chain reaction analysis. Compared with those in poorly metastatic PLA801C subline, cytokeratin 18, tissue transglutaminase, Rho GDP-dissociation inhibitor 1, tropomyosin, fibroblast type, IL-18 and annexin I were significantly up-regulated, while protein disulfide isomerase, heat shock protein 60, peroxiredoxin 1, chlorine intracellular channel protein 1 (CLI1) and creatine kinase, B chain were significantly down-regulated in the highly metastatic PLA801D subline. Intriguingly, all the identified candidate proteins except for CLI1 have been shown to be somehow associated with distinct aspects of tumor metastasis such as cell growth, motility, invasion, adhesion, apoptosis and tumor immunity, etc. Considering that IL-18 was present in highly metastatic PLA801D but absent in poorly metastatic PLA801C, the association of IL-18 with metastasis was further elucidated by introducing IL-18 sense/IL-18 antisense into PLA801C/PLA801D sublines simultaneously. The results demonstrated that ectopically expressed IL-18 promoted cell motility in vitro and down-regulated E-cadherin expression of PLA801C transfectants, while IL-18 antisense remarkably decreased cell invasion potency in vitro and notably increased E-cadherin expression of PLA801D transfectants, indicating that IL-18 might play a role in metastasis by inhibiting E-cadherin expression.     

沼泽山雀繁殖习性的研究

沼泽山雀 Parus palustris Linné的繁殖习性,国内仅有郑作新、钱燕文(1958)在河北昌黎果区对Parus palustris hellmayri Bianchi作过部分观察工作,La Touche(1930)、Wilder and Hubbard(1938)、清栖辛保(1954)、郑光美(1963)等对沼泽山雀的营巢场所、巢卵特点等有所记述,但系统的繁殖习性观察工作尚未见有报导。 1963—1964两年的3—6月间,我们在辽宁草河口林区对Parus palustris brevirostris(Taczanovski)的繁殖习性进行了观察,所得结果如下。     

<Emphasis Type="Italic">Pseudomonas stutzeri</Emphasis> as a novel biocatalyst for pyruvate production from<Emphasis Type="SmallCaps"> DL</Emphasis>-lactate

Pseudomonas stutzeri SDM oxidized dl-lactic acid (25.5 g l^-1) into pyruvic acid (22.6 g l^-1) over 24 h. Both NAD⁺-independent d-lactate dehydrogenase and NAD⁺-independent l-lactate dehydrogenase were found for the first time in the bioconversion of lactate to pyruvate based on the enzyme activity assay and proteomic analysis. Jianrong Hao and Cuiqing Ma contributed equally to this work     

Fluorescence spectrometric study on the interaction of tamibarotene with bovine serum albumin

The interaction between tamibarotene and bovine serum albumin (BSA) was studied using fluorescence quenching technique and ultraviolet–visible spectrophotometry. The results of experiments showed that tamibarotene could strongly quench the intrinsic fluorescence of BSA by a dynamic quenching mechanism. The apparent binding constant, number of binding site and corresponding thermodynamic parameters at different temperatures were calculated respectively, and the main interaction force between tamibarotene and BSA was proved to be hydrophobic force. Synchronous fluorescence spectra showed that tamibarotene changed the molecular conformation of BSA. When BSA concentration was 1.00 × 10^?6 mol L^?1, the quenched fluorescence ΔF had a good linear relationship with the concentration of tamibarotene in the range 1.00 × 10^?6 to 12.00 × 10^?6 mol L^?1 with the detection limit of 6.52 × 10^?7 mol L^?1. Copyright © 2010 John Wiley & Sons, Ltd.     

Spectral Test Instrument for Color Vision Measurement

Common displays such as CRT or LCD screens have hmlted capabilities in displaying most color spectra correctly. The main disadvantage of these devices is that they work with three primaries and the colors displayed are the mixture of these three colours. Consequently these devices can be confusing in testing human color identification, because the spectral distribution of the colors displayed is the combined spectrum of the three primaries. We have developed a new instrument for spectrally correct color vision measurement. This instrument uses light emitting diodes (LEDs) and is capable of producing all spectra of perceivable colors, thus with appropriate test methods this instrument can be a reliable and useful tool in testing human color vision and in verifying color vision correction.     

龟板炮制前后氨基酸的分析

<正> 龟板系龟科动物鸟龟(Chinemgs ree-vsii)的腹甲,为传统滋补中药,具有滋阴潜阳,益肾强骨,养心补血的功效,主要有效成分为多种氨基酸。龟板一般按药典规定的方法经炮制后作为药用。有关氨基酸的系统分析,国内外尚未见报导。为了探讨龟板的内在质量、同时比较其炮制前后氨基酸含量的变化,我们对龟板中所含游离氨基酸及其水解后的氨基酸进行了分析研究。分析结果表明,炮制前的样品中含有I7种游离氨基酸,炮制后则只含有15种游离氨基酸,且前者含量明显高于后者;龟板炮制前后的样品经盐酸水鲜后均测得17种氨基酸,且前者含     

酶制剂在洗涤和纺织行业的应用

洗涤用酶是仅次于食品与饮料行业的第二大工业酶制剂市场。本文介绍了蛋白酶、淀粉酶、脂肪酶和其他碳水化合物酶在洗涤上的作用原理、应用配方及其市场发展。洗涤剂生产配方的改变及由于生物科技的进步而导致酶的有效性和生产效率的提高,使得酶制剂在洗涤剂中拥有良好的应用前景。纺织方面,除非有新的酶制剂和过程技术出现,否则行业会相对增长较慢;新的过程如全酶法纺织加工如果能顺利商业化,则可带来新的增长点。纺织和洗涤行业的酶制剂虽然不像食品有关行业审批那么繁琐,但有关酶制剂可能引起的过敏反应应引起足够的重视和安全使用。     

The Conservation Status of Hong Kong's Tree Flora

1IntroductionHongKongliesonthesouthcoastofChinabetweenlatitudes22?9'-22?TNandlon-gitudesl13?2'Nl14?0'E.ItconsistsofasectionoftheChinesemainland(KowloonandtheNewTerritories,782km2)andnumerousislands,ofwhichthelargestareLantauIsland(142km2)andHongKongIsland(78km2).Thetotalareais1076km2.Thetopographyisextremelyrugged,reaching957matthehighestpoint,TaiMoShah,intheNewTerrito-ries.HongKong'spopulationof6millionpeopleisconcentratedonthelimitednaturalflatland,whichhasbeenextendedbycoastalrecla…