Collaborative Research: IDBR: Nanopore optical biosensor development for analyzing membrane protein interactions

膜蛋白是最重要的一类分子，代表了一半以上的药物靶标，也是最不了解的一类分子之一。该奖项旨在利用纳米制造、纳米光学、微流体和蛋白质工程方面的新技术，开发一种纳米孔膜生物传感器，这有可能改变膜蛋白的研究。这种实时成像仪器将利用薄金膜上的周期性纳米孔来测量膜结合受体和配体之间的结合动力学和亲和性——这是一项非常理想的任务，但现有的亲和性生物传感器（如BIAcoreTM）很少实现。一层带有周期性纳米孔的金薄膜将同时充当支撑细胞膜的机械支架以及无标签表面等离子体共振（SPR）传感器。配体与固定膜受体的结合将显著调节光通过金属纳米孔的传输，这将被记录为高分辨率的实时“电影”。该系统将与微流体集成，以减少样品消耗并实现多路复用。虽然该仪器将适用于分析在接近天然脂质双分子层环境中的任何膜蛋白，但初步研究将与控制细胞免疫的关键识别事件一起进行。在高通量和高分辨率下对膜受体进行配体筛选的能力将为研究这些分子及其实现的基本生命过程提供突破。支持的和独立的脂质膜与纳米孔SPR传感器的集成将为膜蛋白相互作用的动态探测提供一种全新的方法，而不是对现有的SPR仪器进行增量改进。为了鼓励生物团体采用这项技术，明尼苏达大学（http://www.nano.umn.edu/biomems09/）的一个为期两天的短期课程将扩展到纳米孔阵列的制作，而软件和制作协议将在研究网站上免费提供。为了激发未被充分代表的群体对STEM研究的兴趣，SPR和蛋白质蛋白质结合实验将被纳入一个涵盖中学到研究生的培训计划，特别强调本科生。

Membrane proteins are one of the most important classes of molecules, representing over half of drug targets, and also one of the most poorly understood classes. This award is to leverage new technologies in nanofabrication, nano-optics, microfluidics and protein engineering to develop a nanopore membrane biosensor, which has the potential to transform membrane protein research. This real-time imaging instrument will exploit periodic nanopores patterned in a thin gold film to measure the binding kinetics and affinities between membrane-bound receptors and ligands - a task that is highly desirable but is rarely achieved with existing affinity biosensors such as BIAcoreTM. A thin gold film perforated with periodic nanopores will concurrently act as a mechanical scaffold to support cell membranes as well as a label-free surface plasmon resonance (SPR) sensor. Binding of ligands to immobilized membrane receptors will sharply modulate the light transmission through metallic nanopores, which is recorded as a real-time "movie" with high resolution. The system will be integrated with microfluidics to reduce sample consumption and enable multiplexing. While this instrument will be applicable to analyze potentially any membrane protein in a near-native lipid bilayer environment, initial studies will be performed with the key recognition events controlling cellular immunity. The ability to perform ligand screening for membrane receptors at high throughput and high resolution would present a breakthrough in studying these molecules and the fundamental life processes they enable.The integration of supported and free-standing lipid membranes with nanopore SPR sensors will provide an entirely novel approach for dynamic probing of membrane protein interactions, rather than adding incremental improvements to existing SPR instruments. To encourage adoption of the technology by biological groups, a two-day short course at the University of Minnesota (http://www.nano.umn.edu/biomems09/) will be expanded to include nanopore array fabrication, while the software and fabrication protocols will be freely available on the research website. To excite underrepresented groups about STEM research, SPR and protein-protein binding experiments will be incorporated into a training plan spanning middle-school through graduate students, placing special emphasis on undergraduates.