E. coli Gyrase
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E. coli Gyrase
DNA gyrase is a bacterial type II topisomerase which can introduce negative supercoils into DNA. It is a target for both quinolone and coumarin drugs and can be used for screening potential antibacterial compounds. It is prepared from the over producing strains JMtacA and JMtacB1 and is supplied as an A2B2 complex.
Store at -80°C.
All enzyme is supplied with 5X concentrated Assay Buffer and Dilution Buffer which are also available separately. 1 U of gyrase will supercoil 0.5 µg relaxed pBR322 DNA in 30 minutes at 37°C.
See technical documents below for more detailed information and lot specific activities.
Technical Documents
E. coli Gyrase Supercoiling Assay Kits
Kits are available containing everything required to perform supercoiling reactions and to test inhibitors. They contain the enzyme, relaxed DNA substrate and the Assay and Dilution buffers.
Technical Documents
E. coli Gyrase Cleavage Assay Kits
Some drugs interrupt the DNA breakage-reunion step of the gyrase reaction. This leads to cell death and it is the mechanism behind the action of the quinolones such as nalidixic acid and ciprofloxacin. Cleavage assays are particularly useful in determining if a potential drug acts by this mechanism.
These kits are designed specifically for cleavage reactions. They contain the supercoiled pBR322 DNA substrate and the Assay and Dilution buffers required for DNA cleavage reactions in addition to the enzyme and linearised pBR322 marker.
Cleavage specific enzyme available separately on request.
Technical Documents
E. coli Gyrase Assay Kits for Cell Extracts
These kits are designed for assaying cell extracts containing E. coli gyrase and partially purified fractions and contain relaxed DNA substrate, Assay buffer, Dilution buffer and control supercoiled DNA.
Technical Documents
E. coli Gyrase ATPase Kits
These kits can be used to test the effects of potential ATPase inhibitors. For example, the coumarin drugs such as novobiocin inhibit the action of DNA gyrase by competitively inhibiting the hydrolysis of ATP thus preventing supercoiling.
These assays are microtitre plate-based and thus large numbers of compounds can be screened in a relatively short period of time. They also continuous assays which can provide more information than an end point assay.
Technical Documents
High / Medium-Throughput Assay Kit - E. coli Gyrase
The kit is supplied with sufficient E. coli gyrase enzyme, plasmid DNA substrate, buffers and other assay components for 100 assays. The enzyme is supplied at a concentration of 5 U/μl in Dilution Buffer. The kit is also supplied with sufficient wash buffers for one 96-well plate. These buffers are supplied as 20X concentrates and must be diluted with ultra pure water prior to use.
More information about this assay can be found on the "Services" page under "High/Medium Throughput Assay".
Kit issued with limited licence for individual use only.
Patent held by Inspiralis Ltd., Norwich, Norfolk, UK. (Patent No. GB0424953.8, US7838230)
Technical Documents
References
- Hallett, P., Grimshaw, A.J., Wigley, D.B. and Maxwell, A. (1990) Cloning of the DNA gyrase genes under tac promoter control: overproduction of the gyrase A and B proteins. Gene 93: 139-142
- Maxwell, A., Burton, N.P. and O"Hagan, N. (2006) High-throughput assays for DNA gyrase and other topoisomerases. Nucleic Acid Res. 34 (15), e104
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酶抑制剂新药发现的途径:一是来源于天然化合物,包括动植物和各种微生物等,二是化学合成物。在目前上市的药物中,以受体为作用靶点的药物占52%,以酶为靶点的药物占22%,以离子通道为靶点的药物占6%,以核酸为靶点的药物占3%。因此,酶抑制剂的开发是新药来源的一个主要途径。以酶为靶点开发新药存在巨大潜力,今后很长一段时间仍然是发现新药的重要着手点。
如果女方的该基因为双显,则后代不会换此病(基因突变除外,所有基因都可能突变,但概率何其小);如果女方为单显,则男孩有一半的概率致病,女孩不会致病;如果女方也为隐性,则男孩致病,那就要个女孩吧。
结论,能不能生育去医院做精液检查就清楚了,如果可育,再让女方做个DNA鉴定以决定生儿育女。
USANA的产品荣获美国药典(PDR)推荐、加拿大药典(CPS)推荐、香港药品手册(MIMS)推荐、台湾药品手册(MIMS)推荐等八个国家的药店作为医生处方签的依据
· USANA以96.1的最高分荣获第三版《北美营养品评鉴指南》杂志(Comparative Guide to Nutritional Supplement)第1名。
所以建议你购买USANA心脏宝中的辅酶q10,专利水溶性配方高于市面同类产品4倍功效,更容易被人体吸收。
Nutrition.2005Jul-Aug;21(7-8):838-47.
OBJECTIVE:Involvementoflipoxygenase(LOX)andcyclo-oxygenase(COX)oncellulardifferentiationorapoptosisinducedbybutyratehasbeenreportedrecently,buttheeffectontightjunction(TJ)permeabilityhasnotbeenreported.Onemajoractivityofbutyrateand,toalesserextent,propionateistomodulategenetranscriptionviahistoneacetylationbytheirhistonedeacetylaseinhibitoractivity.Inthisstudy,weevaluatedtheactivationofLOXandCOXinTJpermeabilitychangesbyshort-chainfattyacids,butyrate,propionate,andacetateinintestinalmonolayercellsandtheirpossIBLemechanismbyhistoneacetylation.METHODS:TheeffectsofLOXandCOXinhibitorsonTJpermeabilityandtheexpressionofLOXorCOXmRNAinducedbyshort-chainfattyacidswereinvestigatedinCaco-2cellsusingTranswellchambers.Theeffectsofhydroxyeicosatetraenoicacid(aproductofLOX)onTJpermeabilitywerealsoevaluated.Theeffectsofshort-chainfattyacidswerecomparedwiththoseoftrichostatinA(histonedeacetylaseinhibitor).RESULTS:ALOXinhibitorclearlyinhibitedtheeffectofbutyrateonTJpermeability,whereasCOXinhibitorsdidnot.TheLOXandCOXinhibitorspartlyinhibitedtheeffectsofpropionatebutnotofacetate.ButyrateincreasedLOXmRNAexpression,andhydroxyeicosatetraenoicacidandtrichostatinAmimickeditseffect.CONCLUSION:Theseresultssuggestthatshort-chainfattyacids,especiallybutyrate,induceTJpermeabilitychangesthroughLOXactivationthroughhistoneacetylation.
在肠腔,短链脂肪酸可以通过激活脂肪氧化酶的活性从而改变单层细胞间紧密连接的通透性
目的:最近,有文献报道了丁酸盐可以诱导细胞的分化或者凋亡,并且这种效应与脂肪氧化酶(LOX)以及环氧合酶(COX)有关,但是,关于丁酸盐对紧密连接的影响目前未见报道。人们已经知道,丁酸盐以及丙酸盐都可以通过他们对组蛋白去乙酰化酶的抑制作用从而引起组蛋白的乙酰化,并最终实现对基因转录的调控。在我们的研究中,我们研究了短链脂肪酸、丁酸盐、丙酸盐以及醋酸盐对肠上皮细胞间紧密连接通透性的影响,以及这种变化过程中LOX和COX的活化情况,并且研究了这些物质引起组蛋白乙酰化的可能机制。
方法:实验者利用Caco-2细胞以及Transwell小室建立肠腔的体外模型,研究了几种LOX、COX抑制物质对紧密连接通透性的影响,以及对LOX、COXmRNA水平的影响。同时,还研究了羟基二十碳四烯酸(这是一种LOX的催化产物)对TJ通透性的影响。在实验中,研究者还将几种短链脂肪酸的效应与曲古抑菌素A(一种组蛋白去乙酰化酶抑制剂)的效应进行了比较。
结果:使用LOX抑制剂能够明显的抑制丁酸盐所引起的紧密连接通透性的增加,而COX抑制剂则没有这种作用。丁酸盐能够增加细胞中LOXmRNA的表达水平,而羟基二十碳四烯酸以及曲古抑菌素A也都有类似的作用。
结论:以上结果表明,短链脂肪酸,尤其是丁酸盐,能够通过对组蛋白的乙酰化作用活化LOX,并且导致肠上皮细胞间紧密连接通透性的增加。
Luciferase
)
标记细胞或
DNA
,而荧光技术则采用绿色荧光蛋白、红色荧光蛋白等荧光报告基因和
FITC
、
Cy5
、
C
y7
等荧光素及量子点
(quantumdot
,
QD)
进行标记。
小动物活体成像技术是采用高灵敏度制冷
CCD
配合特制的成像暗箱和图像处理,使得可以直接监
控活体生物体内的细胞活动和基因行为。实验者借此可以观测活体动物体内肿瘤的生长及转移、
感染性
疾病发展过程、特定基因的表达等生物学过程。
由于具有更高量子效率
CCD
的问世,使活体动物体内光学成像技术具有越来越高的灵敏度,对肿瘤微
小转移灶的检测灵敏度极高;另外,该技术不涉及放射性物质和方法,非常安全。因其操作极其简单、
所得结果直观、
灵敏度高、
实验成本低等特点,
在刚刚发展起来的几年时间内,
已广泛应用于生命科学、
医学研究及物开发等方面