1. Interlinked DNA nano-circles for measuring topoisomerase II activity at the level of single decatenation events.
- Author
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Kristoffersen EL, Givskov A, Jørgensen LA, Jensen PW, W Byl JA, Osheroff N, Andersen AH, Stougaard M, Ho YP, and Knudsen BR
- Subjects
- Antigens, Neoplasm analysis, Antigens, Neoplasm metabolism, Base Sequence, DNA Topoisomerases, Type II analysis, DNA, Catenated genetics, DNA-Binding Proteins analysis, DNA-Binding Proteins metabolism, HeLa Cells, Humans, Recombinant Proteins analysis, Recombinant Proteins metabolism, Substrate Specificity, DNA Topoisomerases, Type II metabolism, DNA, Catenated chemistry, DNA, Catenated metabolism
- Abstract
DNA nano-structures present appealing new means for monitoring different molecules. Here, we demonstrate the assembly and utilization of a surface-attached double-stranded DNA catenane composed of two intact interlinked DNA nano-circles for specific and sensitive measurements of the life essential topoisomerase II (Topo II) enzyme activity. Topo II activity was detected via the numeric release of DNA nano-circles, which were visualized at the single-molecule level in a fluorescence microscope upon isothermal amplification and fluorescence labeling. The transition of each enzymatic reaction to a micrometer sized labeled product enabled quantitative detection of Topo II activity at the single decatenation event level rendering activity measurements in extracts from as few as five cells possible. Topo II activity is a suggested predictive marker in cancer therapy and, consequently, the described highly sensitive monitoring of Topo II activity may add considerably to the toolbox of individualized medicine where decisions are based on very sparse samples., (© The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2017
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