Tripping the light fantastic: elucidating global protein structural change correlated with chemical change across the femtosecond to second timescale

化学的核心是原子键的形成和断裂过程，由于原子键的时间尺度非常快，性质非常小，所以很难直接观察到这一事件。换句话说，建造一台“分子相机”可能会让记录这些快速和微小的事件直到最近才成为现实。X-FEL(X射线自由电子激光)系统的出现使记录这种分子电影成为现实，尽管这在技术上仍然是一项极具挑战性的壮举。由光触发原子键重组的系统非常适合作为这些尖端研究的初始对象，因为研究人员(即摄像师)可以通过(激光)照明来控制事件。我们试图确定两种不同类型的生物光感受器如何对光做出反应，将最初的原子键重组与蛋白质结构的瞬时变化结合起来，最终导致有机体的光驱动反应。这将使我们能够制定一般蛋白质动态行为的新模型，这将影响生物催化、生物材料、治疗性抗体/蛋白质生产以及健康和疾病中蛋白质动态行为/错误折叠的研究领域。最终，这些光感受器的全部特征将与这些系统的合理工程相结合，以产生一系列根据它们对不同波长/颜色的光的反应而产生的变体。这将生产特征良好的光响应部件，用于控制基于生物的高价值化学品的生产。确定这种控制的最理想的方法是通过光遗传学：通过利用光作为非侵入性和无毒的开关来调节连续微生物发酵过程中的基因表达，可以实现对工程生物合成途径的简单控制。

At the heart of chemistry lies the process of atomic bond formation and breakage, an event that is very difficult to directly observe due to the extremely fast timescale and the very small nature of the atomic bond. In other words, the construction of a 'molecular camera' that might allow the recording of these fast and tiny events only recently become a reality. The advent of X-FEL (X-ray Free Electron Laser) systems has made the recording of such molecular movies a reality, although this remains an extremely technically challenging feat to achieve. Systems where atomic bond reorganisation is trigger by light are ideally suited as initial subjects for these cutting-edge studies as the researcher (ie the camera man) can control the event through (laser) illumination. We seek to determine how two distinct type of biological photoreceptors respond to light, coupling the initial atomic bond reorganisation to the transient change in protein structure that ulimately leads to a light-driven response by the organism. This will allow us to formulate new models for general protein dynamic behaviour, which will impact the areas of biocatalysis, biomaterials, therapeutic antibodies/protein production and the study of protein dynamic behaviour/misfolding in health and disease. Ultimately, the full characterisation of these photoreceptors will be combined with the rational engineering of these systems to produce a range of variants in terms of their response to light of various wavelenghts/colour. This will produce well-characterised light-responsive parts for control of bio-based production of high-value chemicals. The most desirable way to assert this control is through optogenetics: by using light as a non-invasive and non-toxic switch to modulate gene expression during continuous microbial fermentation, simple control of engineered biosynthetic pathways can be achieved.