Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China.
Analyst. 2013 Oct 21;138(20):5989-94. doi: 10.1039/c3an01291c. Epub 2013 Aug 15.
It is of substantial interest to mimic mechanisms of biological sensing systems for the development of novel biosensors. This paper presents a novel biomimetic bitter receptor-based biosensor for the detection of specific bitter substances, in which bitter receptors were used as sensitive elements for the first time. A simple and practical self-assembled aptamer-based strategy was proposed for functional immobilization and purification of bitter receptors. A human bitter receptor, T2R4, was expressed on the plasma membrane of HEK-293 cells and fused with a His6-tag on its C-terminal. The membrane fractions containing the expressed T2R4 were extracted and immobilized on the gold surface of a quartz crystal microbalance (QCM) pretreated with a monolayer of self-assembled aptamers that can specifically recognize and capture biomolecules labeled with His6-tags. The QCM device was used to monitor the responses of T2R4 to various bitter stimuli. The results indicate that this biosensor can detect denatonium with high sensitivity and specificity, which is the specific target of T2R4. In addition, this biosensor shows dose-dependent responses to a certain concentration range of denatonium. The sensitivity of bitter receptor-based biosensors prepared by an aptamer-based method is 1.21 kHz mM(-1), which is 2 times higher than that prepared by a SAM-based method. The major advances on bitter receptor immobilization and purification presented in this work could substantially be very useful for developing other membrane receptor-based biosensors and molecular sensor arrays. This bitter receptor-based biosensor has great potential to be used as a valuable tool for bitter detection as well as for the research of taste signal transduction.
模仿生物感应系统的机制对于开发新型生物传感器具有重要意义。本文提出了一种新型基于仿生苦味受体的生物传感器,用于检测特定的苦味物质,其中苦味受体首次被用作敏感元件。本文提出了一种简单实用的基于适体的策略,用于苦味受体的功能固定化和纯化。将人苦味受体 T2R4 表达在 HEK-293 细胞的质膜上,并在其 C 端融合 His6 标签。提取含有表达的 T2R4 的膜部分,并将其固定在石英晶体微天平(QCM)的金表面上,该 QCM 经预处理后具有单层适体,可特异性识别和捕获带有 His6 标签的生物分子。使用 QCM 装置监测 T2R4 对各种苦味刺激的响应。结果表明,该生物传感器可以高灵敏度和特异性地检测到苯甲地那铵,这是 T2R4 的特定靶标。此外,该生物传感器对一定浓度范围内的苯甲地那铵表现出剂量依赖性响应。基于适体方法制备的苦味受体生物传感器的灵敏度为 1.21 kHz mM(-1),比基于 SAM 方法制备的灵敏度高 2 倍。本工作中苦味受体固定化和纯化方面的主要进展对于开发其他基于膜受体的生物传感器和分子传感器阵列具有重要意义。这种基于苦味受体的生物传感器具有作为苦味检测的有价值工具以及用于味觉信号转导研究的巨大潜力。