Cantilever Magnetic Resonance of Biomolecules

描述(由申请人提供)：迫切需要新的工具来确定单个大分子和大分子络合物的三维结构。R01更新应用程序的目标是创建一种“分子显微镜”，能够成像蛋白质或大分子复合体的单个拷贝的质子密度，或绘制电子自旋标记的位置。我们将开发一种能够进行扫描探针核磁共振成像和电子自旋共振成像的分子显微镜。仪器的开发将针对天然的和自旋标记的结合到脂质双层或位于细胞膜中的大分子复合体的研究。我们的具体目标是：(1)利用磁端悬臂梁和力梯度检测磁共振来观察单个氮氧化物标记蛋白质的电子自旋共振(ESR)和观察生物分子中数百个质子的核磁共振(NMR)；(2)了解和缓解(通过样品制备、悬臂设计和自旋调制方案)在低温下真空中超敏感悬臂在表面附近经历的多余力和力梯度噪声，并学习通过在磁共振作用力显微镜中提供更完美的自旋翻转来延长自旋相干时间；(3)开发时间域傅立叶图像编码，提高扫描探头磁共振成像速度。 公共卫生相关性：迫切需要新的工具来确定单个大分子和大分子复合体的三维结构。我们正在开发一种“分子显微镜”，用于对与生物医学相关的纳米级实体进行成像。这样的仪器将极大地影响广泛的生物过程、疾病和疾病。

DESCRIPTION (provided by applicant): New tools for determining the three dimensional structure of single macromolecules and macromolecular complexes are urgently needed. The goal of this R01 renewal application is to create a "molecular microscope" capable of imaging the proton density of, or mapping the locations of electron spin labels in, a single copy of a protein or macromolecular complex. We will develop a molecular microscope capable of scanned-probe nuclear magnetic resonance (NMR) imaging and electron spin resonance (ESR) imaging. Instrument development will be directed towards the study of native and spin-labeled macromolecular complexes bound to a lipid bilayer or located in a cell membrane. Our specific aims are: (1) To exploit magnetic-tipped cantilevers and force-gradient detection of magnetic resonance to observe electron spin resonance (ESR) from a single copy of a nitroxide-labeled protein and to observe nuclear magnetic resonance (NMR) from a few hundred protons in a biomolecule; (2) To understand and mitigate (via sample preparation, cantilever design, and spin modulation schemes) excess force and force- gradient noise experienced by ultrasensitive cantilevers near surfaces in vacuum at cryogenic temperatures and to learn to prolong spin coherence time by giving more perfect spin flips in magnetic resonance force microscopy; and (3) To develop time- domain Fourier image encoding to increase the imaging speed of scanned-probe magnetic resonance. PUBLIC HEALTH RELEVANCE: New tools for determining the three dimensional structure of single macromolecules and macromolecular complexes are urgently needed. We are developing a "molecular microscope" to image nanoscale entities of relevance to biomedicine. Such an instrument would dramatically impact a broad spectrum of biological processes, disorders, and diseases.