Time-Resolved Fourier Transform Infrared Spectroscopy on Plant Cryptochrome

植物隐花的时间分辨傅里叶变换红外光谱

• 批准号: 192356647
• 负责人: Professor Dr. Tilman Kottke
• 金额: --
• 依托单位: Arbeitsgruppe Biophysikalische Chemie und Diagnostik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/192356647?language=en
• 关键词: Time; Resolved; Fourier; Transform; Infrared

Cryptochromes are sensory proteins that act as key players in the regulation of organisms in response to blue light. They set the biological clock in insects and plants and initiate plant development. Furthermore, they act as sensors for the Earth’s magnetic field in insects and putatively in migratory birds. They incorporate oxidized flavin adenine dinucleotide as a chromophore, a derivative of vitamin B2. Absorption of blue light initiates a cascade of events within the protein, most of which have not been resolved yet. As a model system for this project, the photosensitive domain of the plant cryptochrome from the green alga Chlamydomonas is selected. The signalling state of plant cryptochromes is formed by separate transfer of an electron and a proton from the apoprotein to the flavin. We aim at investigating the response of the protein in a time-resolved manner by applying Fourier transform infrared spectroscopy after nanosecond laser excitation. For this purpose, the stepscan methodology needs to be adapted to the specific demands of the cryptochrome system. The response of the apoprotein to the microsecond proton transfer will be monitored and analyzed. Crucial intermediate steps in the photoreaction will be resolved on microsecond and millisecond time scales. The analysis will reveal to which extent proton transfer, secondary structural changes, and redox coupling play a key role in transmission of the signal from the chromophore all the way to the interaction partner.

隐花色素是一种感觉蛋白，在生物体对蓝光的反应中起着关键作用。它们设定昆虫和植物的生物钟，并启动植物的发育。此外，它们还可以作为昆虫和候鸟体内地球磁场的传感器。它们将氧化黄素腺嘌呤二核苷酸作为发色团，维生素B2的衍生物。蓝光的吸收引发了蛋白质内的级联事件，其中大部分尚未解决。作为本项目的模型系统，选择了来自绿色披碱草的植物隐花色素的光敏结构域。植物隐花色素的信号状态是由一个电子和一个质子从脱辅基蛋白分别转移到黄素而形成的。我们的目的是研究在纳秒激光激发后，通过应用傅里叶变换红外光谱的时间分辨的方式的蛋白质的响应。为此，步进扫描方法需要适应隐花色素系统的特定需求。将监测和分析载脂蛋白对微秒质子转移的响应。光反应中的关键中间步骤将在微秒和毫秒的时间尺度上得到解决。该分析将揭示质子转移、二级结构变化和氧化还原偶联在将信号从发色团一路传递到相互作用伙伴的过程中发挥关键作用的程度。