SupercoiledpHOT-1DNAProductDescription SupercoiledpHOT-1DNAisincludedwithTopoIAssayKit,TopoIDrugKit,TopoIIDrugKit,andTopoIVDrugKit. Reference:
Thisplasmidisaperfectsubstrateforassayinganytopoisomerase. pHOT-1isrelativelysmall(<3KB) which is ideal for displaying intermediate topoisomers. Since all topoisomerases display degenerate DNA binding and cleavage sequences, pHOT-1 will effectively support activity for a wide array of topoisomerase. Supercoiled pHOT-1 is a scaled-down derivative of pBR322 and optimized for higher yields. It has one additional feature for researchers who wish to assess human topo I cleavage at a single sequence: we have included the human topoisomerase I preferential binding site (the hexadecameric sequence described by Westergaard and co-workers, see Bonven et al., 1985) that is derived from the tetrahymena ribosomal gene repeat. This construct is useful as a topo I cleavage substrate since the enzyme efficiently cleaves at the hexadecameric site in the absence of camptothecin. This allows the investigator to rigorously evaluate new potential topo I inhibitors because a single background cleavage is a built-in control; if the agent stimulates cleavage at this and/or any other sequence in the fragment that contains the hexadecameric site, prominent cutting is reADIlyrevealed. Typically,itisdifficulttotraptopoIcleavagesonDNA;onemustusemoreenzymesincecleavagecomplexesconsumetheenzymestoichiometrically. Forthisreason,higherlevelsofenzymearerequiredforanalysisofDNAcleavages. Thefragmentcanbeisolatedfromthepolylinkerusingthesitesshownbelow(protocolsinManiatiscloningbook),endlabeledandusedasacleavagesubstrate.
Bonvenetal.,Cell41:541(1985)
美国TopoGEN公司成立于1991年,是一家诊断公司,由一批在拓扑异构酶领域工作和在基础、临床、应用及相关方面研究经验丰富的研究者创建,为以药物开发为基础的拓扑异构酶和机制研发人员提供创新产品和服务。药物筛选试剂盒可以分析拓扑异构酶活性药物,用于癌症化疗和抗菌方面。TopoGEN公司还能提供原核和真核化验拓扑异构酶 (I型,II,IV和旋转酶)检测试剂盒,体外体内诊断均可应用。TopoGEN公司还提供DNA载体、DNA裂解目标、拓扑异构酶抑制剂、拓扑异构酶抗体和相关试剂盒等完整产品线。