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.
