Development of a novel sensing probe using DNA aptamer inhibiting enzymatic activity

A novel sensing probe for adenosine has been developed using the thrombin-inhibiting DNA aptamer fused with the adenosine-binding DNA aptamer. The adenosine aptamer was inserted into the G-quartet structure of the thrombin aptamer to change its inhibitory activity to thrombin upon binding of the adenosine aptamer part to adenosine. This designed aptamer had lower inhibitory activity than that of the original thrombin aptamer, and it was increased in the presence of adenosine. CD spectra of this designed aptamer indicated that its structure was changed by its binding to adenosine. Using this designed aptamer, we were able to detect adenosine by measuring thrombin activity in homogeneous assay.