EAGER: Validating Atomic Force Microscopy Measurements of the Lipid Membrane Dipole Moment

在生物研究仪器开发和生命过程化学项目的共同资助下，化学测量和成像项目为莱斯大学的杰森·哈夫纳教授提供了EAGER奖，该奖项旨在寻找表征生物膜等结构的新方法——生物膜是支持活细胞许多关键生物功能的薄分子片。虽然膜的外部电学性质已被很好地理解，但其内部电学性质尚不清楚。其中一种内部性质是偶极子势，它是由膜中的分子排列引起的。尽管这种潜力已经被研究了几十年，但它是膜中最不为人所知的方面之一。目前对这种电位的大小没有明确的测量，甚至对膜的哪些成分产生这种电位也没有一致的看法。据推测，这种电位显著影响膜生物学，但这种相关性尚未得到证实，因为目前没有令人满意的方法来测量偶极子电位。本项目将进一步发展最近发现的利用原子力显微镜（AFM）测量膜偶极子势的方法。这些活动将产生一种定量工具，用于测量生物膜的重要但鲜为人知的特性，许多关键生物功能的位置和大多数药物分子的作用。学生将以跨学科的方式在实验研究和理论模拟方面得到支持和培训。该项目的研究成果和仪器概念将用于莱斯大学9年级综合物理和化学（IPC）教师培训项目。这项工作还将为Hafner教授实验室的暑期实习教师提供研究经验。

With co-funding from the Instrument Development for Biological Research and the Chemistry of Life Processes programs, the Chemical Measurement and Imaging program is supporting an EAGER award to Prof. Jason Hafner of Rice University, seeking new ways to characterize structures like biological membranes - the thin sheets of molecules that support many critical biological functions of living cells. While the external electrical properties of membranes are well understood, their internal electrical properties are not. One such internal property is the dipole potential, which arises from molecular alignment in the membrane. Although this potential has been studied for decades, it is among the least understood aspects of membranes. There is currently no definitive measure of the size of this potential, or even agreement about which components of the membrane create it. It has been hypothesized that this potential significantly affects membrane biology, but such a correlation has not been confirmed since there is currently no satisfactory way to measure the dipole potential. This project will further develop a recently discovered method to measure the membrane dipole potential using an atomic force microscope (AFM). These activities will result in a quantitative tool to measure an important yet poorly understood property of biological membranes, the site of many critical biological functions and the actions of most drug molecules. Students will be supported and trained in an interdisciplinary manner in both experimental research and theoretical simulations. The research results and instrumentation concepts from this project will be used in 9th grade Integrated Physics and Chemistry (IPC) teacher training programs at Rice. The work will also provide research experiences for summer teacher interns in Prof. Hafner's laboratory.