Department of Chemistry and Centre for Research on Biomolecular Interactions, York University, 4700 Keele St., Toronto, ON, M3J 1P3, Canada.
BAMS Research Group, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium.
Sci Rep. 2022 Jan 7;12(1):133. doi: 10.1038/s41598-021-03958-6.
Artemisinin (ART) is a vital medicinal compound that is used alone or as part of a combination therapy against malaria. ART is thought to function by attaching to heme covalently and alkylating a range of proteins. Using a combination of biophysical methods, we demonstrate that ART is bound by three-way junction and duplex containing DNA molecules. Binding of ART by DNA is first shown for the cocaine-binding DNA aptamer and extensively studied using this DNA molecule. Isothermal titration calorimetry methods show that the binding of ART is both entropically and enthalpically driven at physiological NaCl concentration. Native mass spectrometry methods confirm DNA binding and show that a non-covalent complex is formed. Nuclear magnetic resonance spectroscopy shows that ART binds at the three-way junction of the cocaine-binding aptamer, and that binding results in the folding of the structure-switching variant of this aptamer. This structure-switching ability was exploited using the photochrome aptamer switch assay to demonstrate that ART can be detected using this biosensing assay. This study is the first to demonstrate the DNA binding ability of ART and should lay the foundation for further work to study implications of DNA binding for the antimalarial activity of ART.
青蒿素（ART）是一种重要的药用化合物，可单独使用或作为抗疟疾联合疗法的一部分。人们认为 ART 通过共价结合到血红素并烷基化一系列蛋白质而起作用。我们使用多种生物物理方法证明，ART 与包含三链结和双链的 DNA 分子结合。首先，我们展示了 DNA 结合的 ART 可卡因结合 DNA 适体，并对该 DNA 分子进行了广泛研究。等温滴定量热法表明，在生理 NaCl 浓度下，ART 的结合既由熵驱动，又由焓驱动。天然质谱法证实了 DNA 的结合，并表明形成了非共价复合物。核磁共振波谱表明，ART 结合到可卡因结合适体的三链结上，并且结合导致该适体的结构开关变体折叠。使用光致变色适体开关测定法利用这种结构开关能力，证明可以使用该生物传感测定法检测 ART。这项研究首次证明了 ART 的 DNA 结合能力，应该为进一步研究 DNA 结合对 ART 抗疟活性的影响奠定基础。
