可光激活绿色光蛋白的结构和机制
J Nathan Henderson1, Rinat Gepshtein, Josef R Heenan
1Institute of Molecular Biology and Department of Physics, University of Oregon, Eugene, Oregon 97403-1229, USA.
Journal of the American Chemical Society
|March 13, 2009
概括
可光激活的绿色光蛋白 (PA-GFP) 晶体结构显示,UV诱导的Glu222脱碳化驱动光激活. 这种机制与稳定突变相结合,比野生型GFP增强了100倍的对比.
科学领域:
- 结构生物学是结构生物学.
- 生物物理学的生物物理.
- 光蛋白工程是指光蛋白质的工程.
背景情况:
- 光激活绿色光蛋白 (PA-GFP) 是活细胞成像的一个有价值的工具.
- 了解PA-GFP的光激活机制对于优化其使用至关重要.
- 以前的研究表明光激活涉及染色体变化,但缺乏详细的结构证据.
研究的目的:
- 阐明PA-GFP光激活的结构基础.
- 为了确定Glu222残留在光激活过程中的作用.
- 了解T203H突变如何促进增强对比度.
主要方法:
- 在原生和光活性状态下解决PA-GFP的晶体结构的X射线晶体学.
- 用光谱分析来研究光特性.
- 生物化学试验证实了Glu222脱碳化作用.
主要成果:
- 晶体结构显示出原生和光活性PA-GFP的不同形状.
- 光激活与Glu222侧链的紫外线诱导脱碳化无疑有关.
- T203H突变稳定了中性染色体,增强了Glu222脱碳化作用.
- 与野生型GFP相比,观察到100倍的对比度增强.
- 获得了对光谱差异和激发状态质子转移动态的洞察力.
结论:
- 在结构上,PA-GFP光激活是由Glu222脱碳化驱动的,将染色体转移到阴离子形式.
- 通过稳定中性染色体,T203H突变显著增强了PA-GFP的可光激活性质.
- 这些发现为PA-GFP功能提供了详细的分子理解,并指导了未来的光蛋白设计.
更多相关视频
11:51Engineering 'Golden' Fluorescence by Selective Pressure Incorporation of Non-canonical Amino Acids and Protein Analysis by Mass Spectrometry and Fluorescence
Published on: April 27, 2018
10:31Residue-Specific Exchange of Proline by Proline Analogs in Fluorescent Proteins: How "Molecular Surgery" of the Backbone Affects Folding and Stability
Published on: February 3, 2022
相关概念视频
Reporter Genes
Reporter genes are a type of protein-coding gene that are often tagged to a gene of interest. Once inside a target cell, reporter genes usually produce visually identifiable characteristics like fluorescence and luminescence when expressed along with the gene of interest. Thus, reporter genes “report” the presence or absence of genes of interest in an organism, determine the gene expression pattern, or track the physical location of a DNA segment or protein in the cell.
Commonly used reporter...
Commonly used reporter...
The Photochemical Reaction Center
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...
