Cantilever Magnetic Resonance Microscopy of Biomolecules

描述(由申请人提供)：该提案旨在开发显著提高磁共振成像灵敏度的技术。其目标是开发一种“分子显微镜”来检测、分析和成像与生物医学相关的纳米级实体。确定蛋白质结构的工具是生物学研究的核心。迫切需要改进的工具来确定大分子的三维结构和聚集体结构。大多数蛋白质不适合用目前的方法进行分析，因为它们不能被分离出足够多的量，或者因为它们不形成晶体。在这项提案中，我们提出了开发基于悬臂的分子显微镜的计划，该显微镜可以确定蛋白质的单个副本的结构，这是目前任何技术都无法完成的任务。这样的仪器将给结构生物学带来革命性的变化，极大地影响广泛的生物过程、紊乱和疾病。 在这项建议中，我们详细介绍了一种逐步开发用于单个成像的分子显微镜的方法。 基于原子力显微镜和磁共振成像技术相结合的生物分子。我们的具体目标是：(1)以一种新的方式检测核磁共振，作为磁尖微悬臂梁弹性常数的变化；(2)制备和表征适用于单质子悬臂梁检测磁共振的纳米磁体。从实验上探索当一个薄的、超灵敏的硅微悬臂接近表面时可以检测到的最小作用力和弹簧常数变化，以及(3)开发和测试适用于小范围核自旋的磁共振成像协议。

DESCRIPTION (provided by applicant): This proposal aims to develop technology for dramatically increasing the sensitivity of magnetic resonance imaging. The goal is to develop a "molecular microscope" to detect, analyze, and image nanoscale entities of relevance to biomedicine. Tools for determining protein structure are central to biological research. Improved tools for determining the three dimensional structure of large macromolecules and aggregate structures are urgently needed. A majority of proteins are not well suited for analysis by current methods because they cannot be isolated in large enough quantities or because they do not form crystals. In this proposal we present plans for developing a cantilever-based molecular microscope that can determine the structure of a single copy of a protein, a task which no current technology can achieve. Such an instrument would revolutionize structural biology, dramatically impacting a broad spectrum of biological processes, disorders, and diseases. In this proposal we detail a stepwise approach to developing a molecular microscope for imaging single biomolecules based on a marriage of atomic force microscope and magnetic resonance imaging technologies. Our specific aims are: (1) To detect nuclear magnetic resonance in a new way, as a change in the spring constant of a magnetically tipped microcantilever, (2) Fabricate and characterize nanomagnets suitable for single-proton cantilever detected magnetic resonance. Explore experimentally the minimum forces and spring constant changes that can be detected when a thin, ultrasensitive, silicon microcantilever is brought close to a surface, and (3) Develop and test magnetic resonance imaging protocols suited to small ensembles of nuclear spins.