信号适体的设计策略及应用

信号适体兼具有分子识别和信号转导的功能.从随机寡核苷酸库中筛选出的适体,要经过合理设计和筛选后修饰,才具备信号转导功能.信号适体可分为标记和非标记两大类.本文着重介绍荧光标记信号适体的设计策略，包括基于荧光偏振分析标记一个荧光基团,及基于荧光共振能量转移同时标记荧光基团、淬灭基团,或两个荧光基团的信号适体(包括分子信标适体、结构转换和原位标记信号适体).非标记信号适体的设计,有嵌合法、置换法、光转换复合物法,及适体－多聚物偶联法.此外，亦可直接从体外筛选出信号适体.信号适体的诸多优点利于其用于生物传感器及均相液相中实时蛋白识别与定量分析.

Design Strategies and Applications of Signaling Aptamers

Signaling aptamers are aptamer probes that couple molecular recognition to signal transduction. Aptamers do not have signaling capabilities when they are isolated from random-sequence libraries and can be engineered into singal reporters by rational design based post-selection modifications. The existing rational design strategies can be divided into two groups:labled and labled-free signaling aptamers. Different signaling strategies of using one fluorophore labeled aptamers based on fluorescence polarization assay, dual labeled aptamers based on fluorescence resonance energy transfer such as molecular beacon aptamers, structure-switching signaling aptamers and in situ labeled aptamers, or other labeled-free aptamers incuding chimeric aptamer approach, substitution approach, light-switch complex approach and aptamer-polymer conjugate approach are reviewed. In vitro selection approach for generating aptamers that can be immediately transformed into effective signaling probes without the need for further optimization is also described. These singaling aptamers can be a useful tool for the development of biosensors and homogeneous assays especially in real time protien recognition and quantitation which do not require multiple immobilisation or washing steps.