Characterisation of electron transport in bacterial nano-wire proteins through high performance computing and experimentation

日常生活越来越依赖电力来支持运输和通信，以及储存和准备食物。这种情况反映了自Alessandro Volta在200多年前制造出第一个电池以来科学的快速发展。然而，电对人类来说是必不可少的，事实上，自从它们存在以来，所有形式的细胞生命都是如此。这种电来自电子传输链，该电子传输链支持光合作用期间将太阳能储存在糖中，以及利用糖中的能量用于呼吸期间的细胞功能、繁殖和运动。特殊设计的蛋白质支持光合作用和呼吸过程中的电子传递。这些蛋白质中的许多含有金属离子，这些金属离子以规则的间隔定位在由氨基酸制成的聚合物中，我们可以立即看到与我们的移动的电话，烤面包机等中移动电子的更大的电缆和电线的结构相似。然而，当溶解在水中时，特定的氨基酸结构决定了这些蛋白质内部和之间的电子转移速率的方式还不太清楚。在这里，我们建议通过计算和实验方法相结合，提供这些机制的洞察力。我们研究的对象是一种含铁蛋白质，其三维结构仅在几个月前才得到解决。这种蛋白质是一个结构相关但功能不同的蛋白质大家族的代表，这些蛋白质最近才被认识到。这些蛋白质使微生物能够在各种明显不适宜居住的环境中定居。它们有助于某些微生物燃料电池的运作，并有助于许多能够感染人类和动物的微生物的毒力。通过解决这些蛋白质的电子传递的分子基础的细节，我们将提供一个广泛的和重要的生物电子传递机制的基本见解。一些计算方法已经存在，其中一些需要在研究方案期间开发。新的方法将提供给其他科学家研究其他感兴趣的蛋白质。所获得的知识还将为开发具有定制电特性的蛋白质提供框架，用于生物电子工程中的分子纳米线。

Day to day life is increasingly reliant on electricity to support transport and communications in addition to the storage and preparation of food. This situation reflects rapid scientific developments since Alessandro Volta built the first battery just over 200 years ago. However electricity has been essential to humans, and indeed all forms of cellular life, ever since they have existed. This electricity arises from the electron transport chains underpinning the storage of solar energy in sugars during photosynthesis and the harnessing of the energy in sugars for cellular function, reproduction and motility during respiration. Specially designed proteins support electron transport during photosynthesis and respiration. Many of these proteins contain metal ions positioned at regular intervals within a polymer made of amino acids and we can immediately see parallels to the structures of the much larger cables and wires that move electrons in our mobile phones, toasters etc. The properties determining the flow of electrons through cables and wires are well established. However, the means by which a particular amino acid structure defines the rate of electron transfer within and between such proteins when dissolved in water is less well understood. Here we propose to provide insight into these mechanisms through a combination of computational and experimental methods. The subject of our study is an iron-containing protein, whose three-dimensional structure has been solved only a few months ago. This protein is a representative of a large family of structurally related, but functionally distinct, proteins that has been recognised only recently. These proteins allow microbes to colonise diverse and apparently inhospitable environments. They contribute to the operation of some microbial fuel-cells and to the virulence of numerous microbes capable of infecting humans and animals. By resolving the molecular details underpinning electron transport through these proteins we will provide fundamental insight into a wide-spread and important mechanism of biological electron transport. Some of the computational methods are already available and some of them need to be developed during the research programme. The new methodologies will be made available to other scientists for studying other proteins of interest. The knowledge gained will also provide the framework for developing proteins with bespoke electrical properties for use as molecular nano-wires in bioelectronic engineering.