Scanning Ion Conductance Microscopy Using Protein Channels

该项目由国家科学基金会化学部的化学测量和成像计划资助。巴尔的摩县马里兰州大学（UMBC）的Ryan白色教授和他的团队正在开发一种新的化学成像平台，该平台使用与生物细胞相同的分子机制来绘制和识别具有单分子灵敏度的特定分子的位置。该项目与理解大脑倡议有关。这项研究依赖于将穿过细胞膜的蛋白质结合到脂质双层中，以观察小分子穿过膜的运动。使用扫描离子电导显微镜提供的优点是提供有关细胞膜上发生的过程的化学信息。这项工作的长期目标是绘制出细胞环境中特定分子的浓度，以更好地了解细胞通讯的分子基础。这项工作的更广泛的影响包括提供一个强大的跨学科背景化学，生物分析和生物化学从事研究的学生。代表性不足的群体被纳入了UMBC促进科学的几个项目。更广泛的科学影响是引入了一种新的成像能力，扫描离子电导显微镜。从长远来看，基于蛋白质通道的方法可以应用于广泛的生物系统的研究。本提案的目标是开发一种生物启发的，基于蛋白质通道的扫描离子电导显微镜（SICM），用于同时进行表面成像和特定分子浓度绘图。该方法依赖于将天然存在的跨膜蛋白通道作为可再现的纳米孔（直径约1 nm）并入，其具有由感兴趣的特定分子门控的活性。白色教授和他的团队正在定量确定影响生物灵感SICM测量分辨率的因素，包括成像移液管尺寸和嵌入蛋白质通道的数量。扫描离子电导显微镜（SICM）的强大成像能力与蛋白质通道测量的特异性和灵敏的单分子检测能力的耦合提供了成像分辨率和特异性分子检测能力的量化。该研究可能为扫描探针显微镜领域提供新的知识，并可能为当前方法无法获得的特定分子引入新的化学成像能力。

This project is funded by the Chemical Measurement and Imaging Program of the Chemistry Division in the National Science Foundation. Professor Ryan White and his team at the University of Maryland Baltimore County (UMBC) are developing a new chemical imaging platform that uses the same molecular machinery that a biological cell uses to map and identify the location of specific molecules with single molecule sensitivity. This project has relevance to the Understanding the Brain initiative. The study relies on incorporating proteins that cross cell membranes into lipid bilayers to look at the movement of small molecules through a membrane. The use of a scanning ion conductance microscope offers the advantage of providing chemical information about processes occurring at the cell membrane. The long-term aim of this work is to map out the concentration of specific molecules in the cellular environment to better understand the molecular basis of cellular communication. The broader impacts of this work include providing a strong interdisciplinary background in chemistry, bioanalysis, and biochemistry to students engaged in the research. Underrepresented groups are included in several programs at UMBC that promote science. The scientific broader impact is the introduction of a new imaging capability to scanning ion conductance microscopy. In the long term, the protein channel-based method may be applied towards studies of a broad range of biological systems.The objective of this proposal is the development a bio-inspired, protein channel-based scanning ion conductance microscope (SICM) for simultaneous surface imaging and specific molecule concentration mapping. The method relies on incorporating naturally-occurring trans-membrane protein channels as reproducible nanopores (~1 nm diameter) with activities that are gated by specific molecules of interest. Professor White and his team are quantitatively determining what affects the resolution of the bio-inspired SICM measurement including imaging pipette dimensions and the number of embedded protein channels. The coupling of the powerful imaging capabilities of scanning ion conductance microscopy (SICM) with the specific and sensitive single molecule detection abilities of protein channel measurements provides quantification of the imaging resolution and specific molecule detection abilities. The research may provide new knowledge to the field of scanning probe microscopy and may introduce a new chemical imaging abilities for specific molecules not accessible with current methodologies.