Development of Atomic Force Microscopic Instrumentation for the Detection of Chemical and Biological Forces

本提案旨在在爱荷华州立大学（ISU）建立一个跨学科的研究项目，利用原子力显微镜（AFM）的原理来检测生物分子力。这一目标将通过在国际滑联成立一个由动物与遗传学系和化学系的科学家组成的合作研究小组来实现，该小组将与国际滑联其他部门的研究人员合作。研究的中心重点将是检测和测量相对简单（如氨基酸）和更复杂（如短肽、蛋白质/核酸、抗体-抗原）生物分子系统之间相互作用中的结合力。从这些研究中获得的信息将为与分子识别、自组装和生物分子系统折叠相关的结合模式提供重要的见解。此外，这些研究将加强新兴的分子力检测技术在生物分析诊断中的应用。该计划的发展分为三个相互关联的项目，所有这些项目都寻求利用AFM及其变体在纳米长度尺度上探测界面结构的能力。这三个项目是：项目一：Tip-Substrate Modification Methods。该项目侧重于开发新的或扩展现有的方法，用于AFM尖端的化学和生物改性。还将设计用于构建空间图案化表面的方法，作为制备不同分子种类的小型局部阵列的平台。项目2：分子力相互作用。本项目使用项目1中创建的材料，通过afm力表征来研究生物材料的分子水平相互作用。该项目从各种接触液体（如有机溶胶喷口和生物介质）下的模型化学系统（如-CO2H， -CH3）的表征开始，发展到越来越复杂的系统（如氨基酸，短肽），并最终研究超分子结构域（如亮氨酸拉链）和整个分子（如抗体/抗原复合物）之间的生物分子力相互作用。项目3：生物分子力显微镜（BMFM）。该项目需要建造第一代AFM，专门用于检测和测量生物材料之间的力。BMFM将以分子力检测的既定设计原则和项目1和项目2的研究结果为基础。为执行上述项目，要求为仪器的购置和建造提供资金，并为与仪器的设计、开发、操作和维护有关的人员和用品提供部分支持。作为机构成本分摊的一部分，国际滑联将为该计划的发展提供仪器和一些研究和培训活动的支持。这种支持远远超出了NSF建议的50%的费用分担，表明国际滑联对该计划的启动和发展的高度承诺。

This proposal seeks to establish an interdisciplinary research program at Iowa State University (ISU) in the detection of biomolecular forces using the principles of atomic force microscopy (AFM). This goal will be accomplished by the formation of a collaborative research group at ISU that is composed of scientists from the Department of Zoology & Genetics and the Department of Chemistry, evolving to include collaborations with investigators in other ISU departments. The central focus of research will be the detection and measurement of the binding forces operative in the interactions between relatively simple (e.g., amino acids) and more complex (e.g., short peptides, protein/nucleic acid, antibody-antigen) biomolecular systems. The information gained from these investigations will provide important insight into the binding modes related to the molecular recognition, self-assembly, and folding of biomolecular systems. Furthermore, these studies will enhance the implementation of emerging molecular force detection techniques in bioanalytical diagnostics. The development of this program is divided into three interrelated projects, all of which seek to take advantage of the ability of AFM and its variants to probe interfacial architectures at nanometer length scales. The three projects are: Project 1: Tip-Substrate Modification Methods. This project focuses on the development of new, or the extension of existing, methods for the chemical and biological modification of AFM tips. Approaches will also be devised for the construction of spatially patterned surfaces as platforms for the preparation of small, localized arrays of different molecular species. Project 2: Molecular Force Interactions. This project investigates the molecular level interactions of biological materials through AFM-force characterizations using the materials created in Project 1. The project starts with characterizations under a variety of contacting liquids (e.g., organic sol vents and biological media) of model chemical systems (e.g., -CO2H, -CH3), progresses to increasingly complex systems (e.g., amino acids, short peptides), and culminates with studies of the biomolecular force interactions between supermolecular domains (e.g., the leucine zipper) and whole molecules (e.g., antibody/antigen complexes). Project 3: The BioMolecular Force Microscope (BMFM). This project entails the construction of a first generation AFM that is designed specifically for the detection and measurement of forces between biological materials. The BMFM will be based on established design principles for molecular force detection and on the findings in Projects 1 and 2. To carry out the above projects, funding is requested for instrumentation acquisition and construction, and for partial support of personnel and supplies associated with the design, development, operation, and maintenance of the instrumentation. As part of the institutional costsharing, ISU will provide support for instrumentation and for several of the research and training activities for the development of this program. This support extends well past the recommended 50% cost share by NSF, demonstrating the high level of commitment by ISU to the initiation and growth of the program.