T4 DNA Ligase

Inspiralis has been supplying T4 DNA ligase for many years. We can supply it in the smaller quantities below or in larger or more concentrated quantities (for example for DNA-tagged chemical library construction).

T4 DNA ligase catalyses the formation of a phosphodiester bond between the terminal 5′ phosphate and a 3′ hydroxyl groups of duplex DNA or RNA. It can ligate cohesive ends of DNA or oligonucleotides, as well as RNA and RNA-DNA hybrids and is particularly efficient at sealing nicks in duplex DNA.  It can also ligate blunt-ended DNA but cannot ligate single-stranded nucleic acids. It requires ATP as a cofactor.

inspiralis高/中通量拓扑异构酶测定John Innes中心的A. Maxwell教授和Inspiralis员工在实验室中开发了一种基于高通量微量滴定板的测定法。基于这样的事实，即负超螺旋质粒比松弛质粒更容易形成分子间三链体DNA。该测定法克服了基于凝胶的测定法的一些问题，这些问题很费时，因此固有地是低通量的。Inspiralis能够提供此测定方法，作为筛选化合物对拓扑异构酶（包括促旋酶，topo IV和人topos I和II）的抑制活性的手段。该测定法适用于改变DNA超螺旋的其他酶，例如限制酶。该测定与常规基于凝胶的测定比较的一些结果如下所示。该测定法对化合物的筛选特别有用，也可用于测定IC 50  值。在以下给出的实施例中，比较了基于板和凝胶的测定法对陀螺IV和人topo I和II对陀螺酶抑制超螺旋和松弛的IC 50值的确定。 在两种测定中均获得了相似的抑制谱和IC 50值。