Structural Studies on Aequorin

水母发光蛋白的结构研究

• 批准号: 9983055
• 负责人: James Head
• 金额: $ 27万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9983055&HistoricalAwards=false
• 关键词: Structural; Studies; Aequorin

The objective of this research is to understand the mechanism of action of the calcium-activated light-emitting protein aequorin. The work will focus on structure determination by X-ray crystallography to identify, at the atomic level, the components of the protein and the chromophoric ligand, coelenterazine, which enable aequorin bioluminescence. Once the structure of the native, calcium-free, holoprotein is determined, the structures of other forms will be studied. These include aequorin after calcium-activation (blue fluorescent protein), aequorin containing modified forms of the chromophore, and aequorin with protein mutations which are designed to establish which residues are involved in the reaction mechanism and how. The mechanism(s) involved in the regeneration, in which the blue fluorescent protein can be converted back to active aequorin, will also be investigated. In addition to understanding the mechanisms of these processes, these studies will also be aimed at producing modified forms of aequorin, by either mutation of the protein or changes in the chromophore, to produce forms with different ion selectivity, responsiveness and emission wavelength.Bioluminescence is a process whereby chemical energy is converted into light by a biological molecule. Many animals use such molecules for signaling; to one another, to enemies or to prey. One such molecule is the protein aequorin. Aequorin has proved of particular scientific value because it emits light in response to the presence of calcium. Despite the extensive laboratory use of aequorin, the details of the mechanism by which it converts chemical energy to light when calcium is added remains poorly understood. This work aims to provide an understanding these details by using x-ray crystallography to determine the position of the individual atoms of aequorin and how they interact with calcium to generate light.

本研究的目的是了解钙激活发光蛋白水母发光蛋白的作用机制。这项工作将侧重于通过 X 射线晶体学确定结构，以在原子水平上鉴定蛋白质和发色配体腔肠素的成分，腔肠素能够实现水母发光蛋白的生物发光。一旦确定了天然的、无钙的全蛋白的结构，就会研究其他形式的结构。这些包括钙激活后的水母发光蛋白（蓝色荧光蛋白）、含有发色团修饰形式的水母发光蛋白，以及具有蛋白质突变的水母发光蛋白，旨在确定哪些残基参与反应机制以及如何参与。还将研究参与再生的机制，其中蓝色荧光蛋白可以转化回活性水母发光蛋白。除了了解这些过程的机制之外，这些研究还将旨在通过蛋白质突变或发色团变化来生产修饰形式的水母发光蛋白，以产生具有不同离子选择性、响应性和发射波长的形式。生物发光是化学能通过生物分子转化为光的过程。许多动物使用这些分子来发出信号。彼此、敌人或猎物。一种这样的分子是蛋白质水母发光蛋白。 水母发光蛋白已被证明具有特殊的科学价值，因为它会根据钙的存在而发光。 尽管水母发光蛋白在实验室中得到广泛使用，但当添加钙时，水母发光蛋白将化学能转化为光的机制的细节仍然知之甚少。这项工作旨在通过使用 X 射线晶体学来确定水母发光蛋白各个原子的位置以及它们如何与钙相互作用以产生光，从而加深对这些细节的理解。