STRUCTURAL STUDIES ON ANTIFREEZE PROTEINS

抗冻蛋白的结构研究

• 批准号: 2398137
• 负责人: FRANK D SONNICHSEN
• 金额: $ 10.17万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2398137
• 关键词: Coleoptera; Osteichthyes; cryoprotective agents; cryoscience; freezing; intermolecular interaction; nuclear magnetic resonance spectroscopy; protein structure function; proteins; site directed mutagenesis; water

Subfreezing temperatures pose a severe threat to the survival of organisms inhabiting polar and subpolar environments. Many organisms, including plants, insects and fish, have adapted and developed protective mechanisms which lower the risk of freezing. Certain fish produce antifreeze proteins, i.e. substances which lower the freezing points of their body fluids by binding to and inhibiting the growth of seed ice crystals. Similar compounds (thermal hysteresis proteins) are currently being isolated from plants and insects. Also, protein- crystal interactions are biologically common and important in processes such as biomineralization and calcification. This research project plans to investigate the structure-function relationship of several antifreeze proteins, characterize their unique activity and identify structural features or common motifs required for activity. The long- term objectives are to improve our understanding of the kinetic and thermodynamic aspects of the protein adsorption to ice in order to identify the source for the observed high binding affinity and mechanism of freezing point depression. The studies will increase our basic understanding on protein-surface and protein-crystal interactions, and are aimed to facilitate the engineering of antifreeze compounds for use in the cryogenic storage of cells, blood and organs, and for conferring freezing resistance to crop and food. My laboratory is dedicated to the structural and mechanistic characterization of a number of distinct classes of antifreeze proteins. The specific aims of this stage of the project will be to utilize homonuclear and heteronuclear multi-dimensional NMR-spectroscopy in combination with site-specific mutagenesis, computational methods and crystallization experiments to: i) determine the three dimensional structure of Type 2 antifreeze protein from herring, ii) determine the solution structure of Type 2 antifreeze protein from sea raven, iii) to determine the structure of a thermal hysteresis protein from the beetle Tenebrio molitor, and iv) to investigate the protein-water and protein-ice interactions of these proteins.

零度以下的气温对生物的生存构成严重威胁 栖息于极地和亚极地环境的生物。 许多生物体， 包括植物、昆虫和鱼类，已经适应并发展了 降低冻结风险的保护机制。某些鱼 产生抗冻蛋白，即降低冷冻的物质 通过结合并抑制其生长来控制其体液的点 种子冰晶。类似的化合物（热滞蛋白）是 目前正在从植物和昆虫中分离出来。 另外，蛋白质—— 晶体相互作用在生物学过程中是常见且重要的 例如生物矿化和钙化。本研究项目 计划研究几个结构与功能的关系 抗冻蛋白，表征其独特的活性并识别 活动所需的结构特征或共同主题。长- 术语目标是提高我们对动力学和 蛋白质吸附到冰上的热力学方面 确定观察到的高结合亲和力的来源，并 冰点降低的机制。这些研究将增加我们 对蛋白质表面和蛋白质晶体的基本了解 相互作用，旨在促进防冻剂的工程设计 用于细胞、血液和器官低温储存的化合物， 以及赋予作物和食品抗冻性。我的实验室 致力于结构和机械表征 许多不同类别的抗冻蛋白。具体目标 该项目此阶段的重点将是利用同核和 异核多维核磁共振波谱与 定点诱变、计算方法和结晶 实验： i) 确定 Type 的三维结构 2 来自鲱鱼的抗冻蛋白，ii) 确定溶液结构 来自海鸦的 2 型抗冻蛋白，iii) 以确定 黄粉虫热滞蛋白的结构 molitor，以及 iv) 研究蛋白质-水和蛋白质-冰 这些蛋白质的相互作用。