核酸适体与互补核酸和目标蛋白之间竞争结合的热力学特性研究

A Thermodynamic Investigation into the Binding Affinity between Aptamer-DNA and Aptamer-protein

以一种基于目标蛋白凝血酶的取代反应来研究核酸适体与互补核酸和核酸适体与目标蛋白之间竞争结合的热力学特性,研究了核酸适体-互补核酸的解离反应和在目标蛋白存在下取代反应的平衡常数、标准焓变和标准熵变等热力学参数,结果表明该取代反应是一个熵驱动的自发过程,熵驱动从双链的核酸转变为核酸适体-目标蛋白的复合物.该热力学研究会对核酸适体-互补核酸和核酸适体-凝血酶之间的结合过程的机理有一个更深的理解,将有助于进一步揭示核酸与蛋白这两种生命中最关键物质之间的相互作用和关系,为更好地理解基本的生物过程和预测设计适体生物传感器,发展用于疾病诊断的方法有着重要的意义.

A thermodynamic investigation into the binding affinities between aptamer-DNA and aptamer-protein based on the displacement reaction for thrombin was presented.Some thermodynamic parameters such as the equilibrium constant,enthalpy and entropy of the dissociation reaction and the displacement reaction were evaluated.The results showed that the change of entropy played an important role in the conversion of the duplex DNA into aptamer-protein binding.This has been the first attempt to compare the stability of the duplex aptamer-DNA and the aptamer-protein complex,and it will provide an insight into how the conformation changes.The obtained thermal parameter will direct us to find out the basic principle for designing the aptamer based biosensor and to deeply understand the thermal properties of the aptamer toward protein,and it will be great importance of developing new methods for disease diagnosis.