Human Topoisomerase II alpha and beta
Click on the product headings below to view details and order online.
Human Topoisomerase II Alpha
Human topoisomerase II alpha is prepared by overexpressing in baculovirus-infected insect cells (Spodoptera frugiperda) and purifying it by methods developed in-house.
The enzyme is supplied in Dilution Buffer.
Store at -80°C.
It is recommended that larger pack sizes (500U and above) of the enzyme are aliquoted to avoid repeated freeze-thaw cycles.
See technical documents below for more detailed information and lot specific activities.
Technical Documents
Human Topoisomerase II Beta
Human topoisomerase II beta is prepared by overexpressing in baculovirus-infected insect cells (Spodoptera frugiperda) and purifying it by methods developed in-house.
The enzyme is supplied at a concentration of 2-10 U/μl in Dilution Buffer.
Store at -80°C. (Stable for 3 months undiluted).
It is recommended that the enzyme is aliquoted to avoid repeated freeze-thaw cycles.
Technical Documents
Human Topoisomerase II Decatenation Assay Kits
These contain human topo II and the catenated kDNA substrate in addition to the Assay and Dilution buffers for decatenation reactions. 1 U of human topo II will decatenate 200 ng of kDNA when incubated in 1X Assay buffer in a total reaction volume of 30 µl at 37°C for 30 minutes. The kits are available with either the alpha or beta forms of the enzyme.
Technical Documents
Human Topoisomerase II Relaxation Assay Kits
These contain human topo II and the supercoiled DNA substrate in addition to the Assay and Dilution buffers for relaxation reactions. 1 U of human topo II will relax 0.5 µg supercoiled pBR322 DNA in 30 minutes at 37°C. The kits are available with either the alpha or beta forms of the enzyme.
Technical Documents
Human Topoisomerase II Assay Kits For Cell Extracts
These kits are designed for assaying cell extracts and partially purified fractions containing human topo II. They contain kDNA substrate, Assay buffer, Dilution buffer, decatenated and linear DNA markers and stop buffer / loading dye.
The kit components are based on the standard assay which contains 500 ng substrate DNA per assay.
Technical Documents
High / Medium-Throughput Assay Kit - Human Topoisomerase II
The kit is supplied with sufficient human topo II enzyme, plasmid DNA substrate, buffers and other assay components* for 100 assays. The enzyme is supplied at a concentration of 10 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. The kits are available with either the alpha or beta forms of the enzyme.
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
Human Topoisomerase II alpha 453 subunit
Human topoisomerase II alpha amino acids 1-453. This contains the ATPase domain, the activity of which can be stimulated by DNA (see Campbell and Maxwell (2002), J.Biol.Chem. 320 p.171. The protein is expressed in E.coli.
Technical Documents
ebiomall.com
>
>
>
>
>
>
>
>
>
>
>
>
肌酸激酶有四种同功酶形式:肌肉型(MM)、脑型(BB)、杂化型(MB)和线粒体型(MiMi)。MM型主要存在于各种肌肉细胞中,BB型主要存在于脑细胞中,MB型主要存在于心肌细胞中,MiMi型主要存在于心肌和骨骼肌线粒体中。肌肉型肌酸激酶分子是由两个相同的亚基组成的二聚体。根据目前已经测定的兔、人、鸡、鼠肌酸激酶的一级结构[3-6],M型亚基由387个氨基酸残基组成,质量为43 KDa左右,分子内有8个巯基,但无二硫键。大熊猫肌肉型肌酸激酶也是二聚体酶,每个亚基由376个氨基酸残基组成,分子量为42 KDa[7]。向左转|向右转
根据PTK是否存在于细胞膜受体可将其分成受体型和非受体型。向左转|向右转
大家好,有几个设计的药物分子需要测试活性,不知道谁能提供下能做相关测试服务的机构或个人信息不?非常感谢!
1、纳豆激酶是在纳豆发酵过程中由纳豆枯草杆菌(Bacillus subtilisl natto)产生的一种丝氨酸蛋白酶(单链多肽酶),分子量为27728道尔顿。
2、纳豆激酶在温度超过80℃时迅速变性失活,但反复冻融对其影响不大。
3、纳豆激酶在PH值从7升至12时,10min内稳定;PH值低于5时,迅速变性失活。胃酸环境中的PH值只有1.2到2之间,纳豆激酶根本无法通过。
4、纳豆激酶与粘性物质混合后,在PH值2-3的酸性环境中,还能保持不超过7.5%的活性。
5、纳豆激酶是大分子的单链多肽酶,可被肠道消化液(糜蛋白酶、胰蛋白酶、小肠液等)分解成氨基酸片段或分子量更小的肽链。
纳豆一词源于日本,是日本发酵食品,源自中国的咸豆豉,但并非中国豆豉,而是由黄豆通过纳豆菌(枯草杆菌)发酵制成豆制品,具有黏性,气味较臭,味道较甜,不仅保有黄豆的营养价值、富含维生素K2、提高蛋白质的消化吸收率,更重要的是发酵过程产生了多种生理活性物质,具有溶解体内纤维蛋白及其他调节生理机能的保健作用。
根据磷酸化的底物不同,可将蛋白激酶分为组蛋白蛋白激酶、酪蛋白蛋白激酶等,但由于蛋白激酶可磷酸化底物的多样化,这种分法很不确切,已经被根据底物磷酸化氨基酸的分类方法所取代,有些如酪蛋白蛋白激酶,只是由于习惯而一直被沿用下来。根据有无调节物将蛋白激酶分为信使依赖的蛋白激酶和非信使依赖的蛋白激酶,有些信使依赖的蛋白激酶的首字母缩略词已为人们所接受,如cAMP依赖的蛋白激酶PKA、钙和磷脂依赖的蛋白激酶PKC以及钙依赖钙调素不依赖的蛋白激酶CDPK等,它们彼此间存在结构和功能上的相关关系。
也有人认为:蛋白激酶在信号转导中主要作用有两个方面:其一是通过磷酸化调节蛋白质的活性,磷酸化和去磷酸化是绝大多数信号通路组分可逆激活的共同机制,有些蛋白质在磷酸化后具有活性,有些则在去磷酸化后具有活性;其二是通过蛋白质的逐级磷酸化,使信号逐级放大,引起细胞反应.
暂无品牌问答