Collaborative Research: Biophysical Analysis of Magnetosome Development in Magnetotactic Bacteria Under Ambient Conditions

合作研究：环境条件下趋磁细菌磁小体发育的生物物理分析

• 批准号: 1504610
• 负责人: Ronald Walsworth
• 金额: $ 39.75万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1504610&HistoricalAwards=false
• 关键词: Collaborative; Research; Biophysical; Analysis; Magnetosome; Collaborative; Research; Biophysical; Analysis; Magnetosome

Central to the survival of many organisms is their ability to manipulate inorganic molecules into elaborate crystalline structures such as skeletons, teeth, and protective shells. This ubiquitous process of "biomineralization" depends on the precise action of specialized proteins within cells to form minerals where they are needed and prevent their accumulation in sensitive tissues. Although progress has been made, much is not understood about how biomineralization is realized inside of individual cells and which genes control the process. This collaborative project will address this challenge by applying recent advances in magnetic imaging technology to detailed studies of biomineralization in a simple and well-controlled biological system: the production of nanoscale magnetic particles within magnetotactic bacteria (MTB), and the use by MTB of chains of these particles (known as magnetosomes) for orientation and travel along the Earth's magnetic field lines (known as magnetotaxis). During this project, students and postdoctoral researchers will receive training in scientific practices at the interface of the physical and life sciences. In addition, the project may inform the development of improved materials with broad practical relevance, as products of biomineralization have superior properties compared to those currently engineered by humans.The scientific goals of this project are to study the molecular mechanisms governing biomineralization and the development of magnetic nanoparticles in MTB. The studies will employ a "diamond magnetic imager" that exploits a nanoscale layer of quantum sensors at the surface of a diamond chip, enabling imaging of magnetic field patterns from individual MTB in a population under ambient laboratory conditions, with better than 50 nanometer spatial resolution and greater than 1 millimeter field-of-view. The investigators will apply the diamond magnetic imager to studies of magnetic nanoparticle growth in various MTB species and biomineralization mutants. The project will open a new window onto the physical processes enabling magnetotaxis, including the transition of magnetic nanoparticles from a superparamagnetic to a stable single-domain magnetic state during magnetic nanoparticle growth, and the role of interactions between magnetic nanoparticles within individual MTB. Magnetic measurements on genetic mutants will provide biological insights into the genes controlling the biomineralization process. Observations will also be made of the dynamics of the magnetic nanoparticle chain during the cell division cycle, both through time series magnetic measurements on different MTB as well as magnetic imaging of individual living MTB.

许多生物生存的核心是它们能够将无机分子操纵成精细的晶体结构（例如骨骼，牙齿和保护性壳）的能力。 这种无处不在的“生物矿化”过程取决于细胞中专门蛋白质在需要的矿物质中的精确作用，并防止它们在敏感组织中的积累。 尽管取得了进展，但对于如何在单个细胞内实现生物矿化以及哪些基因控制过程的生物矿化尚未了解。 这个协作项目将通过将磁成像技术的最新进展应用于一个简单且控制良好的生物学系统中的生物矿化的详细研究来应对这一挑战：在磁性细菌（MTB）内生产纳米级磁性颗粒（MTB），以及这些颗粒链的MTB用途（已知的磁体）（已知的磁性磁体）（众所周知的磁性磁性）（范围为磁性）（范围为磁性）。 在此项目中，学生和博士后研究人员将接受体育和生命科学界面的科学实践培训。 此外，该项目可以为具有广泛实践相关性的改进材料的开发提供信息，因为与人类当前设计的生物矿化产品相比具有优越的特性。该项目的科学目标是研究管理生物矿化的分子机制和MTB中磁性纳米颗粒的发展。 该研究将采用“钻石磁成像仪”，该研究在钻石芯片表面上利用量子传感器的纳米级层，从而在环境实验室条件下对单个MTB的磁场模式进行成像，具有大于50纳米的空间分辨率和大于1毫米计的现场。 研究人员将将钻石磁成像仪应用于各种MTB物种和生物矿化突变体中磁性纳米颗粒生长的研究。 该项目将打开一个新的窗口，直到能够使磁性的物理过程中，包括在磁性纳米粒子生长过程中从超paragnetic转变为稳定的单域磁态，以及单个MTB内磁性纳米颗粒之间相互作用的作用。 基因突变体上的磁测量将为控制生物矿化过程的基因提供生物学见解。 在细胞分裂周期期间，磁性纳米颗粒链的动力学也将进行观察，这既通过时间序列磁性测量，又是对单个活的MTB的磁成像。