适体与茶碱相互作用模式与电化学响应行为研究

Study on the interaction mode and electrochemical response behavior of aptamer to theophylline

建立了适体与茶碱(THE)相互作用模式及其电化学响应行为研究方法。借助分子动力学(MD)模拟技术获取该相互作用体系的动力学变化过程并揭示其相互作用模式,采用单探针适体传感器考察该相互作用体系的电化学信号响应行为,基于相互作用模式定性阐释信号响应行为成因。结果表明,在0.1和0.5 mol/L NaCl的2种离子强度水溶液中,适体与靶标THE呈现为不同的结合方式,诱导适体发生不同趋势的构型变化,导致构建传感器显示“signal off”和“signal on”2种相反的信号响应。模拟结果支持实验结果,为理解适体传感分析性能从分子作用机制层面提供了理论依据。

A new method was established for studying the interaction of aptamer to theophylline(THE)and the electrochemical response behavior.By means of molecular dynamics(MD)simulation technology,the dynamic change process of the interaction system was obtained,and the relevant interaction mode was revealed.The electrochemical signal response behavior based on this interaction system was investigated using a single-probe aptamer-based sensor method,and the cause of signal response behavior was qualitatively explained following the confirmed interaction mode.The results showed that the aptamer and the target presented different binding modes in the aqueous solutions with 0.1 mol/L and 0.5 mol/L NaCl,respectively.This induced the aptamer produced different configuration changes,leading to two opposite signal responses of“signal off”and“signal on”.The simulation results effectively supported the experimental results,providing a theoretical basis for further understanding the practical analysis performance of aptamer sensing from the molecular mechanism level.