Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States.
Bioconjug Chem. 2011 Feb 16;22(2):282-8. doi: 10.1021/bc100402p. Epub 2011 Jan 19.
The rational design of DNA/RNA aptamers for use as molecular probes depends on a clear understanding of their structural elements in relation to target-aptamer binding interactions. We present a simple method to create aptamer probes that can occupy two different structural states. Then, based on the difference in binding affinity between these states, target-aptamer binding interactions can be elucidated. The basis of our two-state system comes from the incorporation of azobenzene within the DNA strand. Azobenzene can be used to photoregulate the melting of DNA-duplex structures. When incorporated into aptamers, the light-regulated conformational change of azobenzene can be used to analyze how aptamer secondary structure is involved in target binding. Azobenzene-modified aptamers showed no change in target selectivity, but showed differences in binding affinity as a function of the number, position, and conformation of azobenzene modifications. Aptamer probes that can change binding affinity on demand may have future uses in targeted drug delivery and photodynamic therapy.
DNA/RNA 适体作为分子探针的合理设计取决于对其结构元件与靶标-适体结合相互作用的清晰理解。我们提出了一种简单的方法来创建适体探针，这些探针可以占据两种不同的结构状态。然后，基于这些状态之间的结合亲和力差异，可以阐明靶标-适体结合相互作用。我们的两态系统的基础来自于在 DNA 链中掺入偶氮苯。偶氮苯可用于光调节 DNA 双链结构的熔化。当掺入适体中时，偶氮苯的光调控构象变化可用于分析适体二级结构如何参与靶标结合。偶氮苯修饰的适体在靶标选择性上没有变化，但结合亲和力随偶氮苯修饰的数量、位置和构象的不同而不同。能够按需改变结合亲和力的适体探针在靶向药物输送和光动力疗法中可能具有未来的用途。
