A biochemical and biophysical analysis of a ubiquitous protein translocation apparatus

地球上生命的一个古老而重要的发展是围绕并形成每个细胞的脂质薄膜的进化。这些膜提供了对水和亲水性溶质的屏障。它们用于将生物反应与外界隔离，并提供分离电荷和相互通信和聚合以形成复杂结构的潜力。更复杂的细胞还包含内部膜结构，为化学反应和电势的产生提供进一步的分裂。这些事件促进了利用能量以及发展和维持细胞的复杂结构和生物化学的能力。在外部和不同隔室之间穿过脂质膜的物质的必要交换引起了小分子和大分子的运输问题。蛋白质是根据细胞质溶胶中每个相应基因的遗传密码制成的氨基酸的大聚合物。为了发挥其特定作用，其中许多人需要被送到其他地点。这需要它们穿过或进入特定的膜。该提案旨在使用细菌细胞膜作为模型系统来更多地了解这一重要过程。负责蛋白质跨膜运动的装置已被纯化。一旦准备好，各个部分将被标记上化学试剂，这些试剂能够通过与光相互作用的方式报告其环境。这些探针将记录组件在跨膜转运蛋白质时所做的运动，这将有助于我们理解这种反应。这一领域的新发现将对蛋白质分泌、细胞生物发生和发育的理解产生影响。此外，它们还将帮助我们了解其他分子机器和更一般的过程，如膜运输。这些信息也可能被用于开发新的抗生素。

An ancient and essential development for life on Earth has been the evolution of a thin film of lipids that surround and form each cell. These membranes provide a barrier to water and hydrophilic solutes. They serve to isolate biological reactions from the outside, and offer the potential to separate charge and to communicate & aggregate with one another to form complex structures. More complicated cells also contain internal membrane structures that provide a further division for chemical reactions and generation of electric potentials. These events facilitated the ability to harness energy and to develop and maintain the complex structures and biochemistry of the cell. The necessary exchange of materials across lipid membranes between the outside and different compartments gives rise to a transport problem for small and large molecules alike. Proteins are large polymers of amino acids made according to the genetic code of each respective gene in the cell cytosol. In order to perform their specific roles many of them need to be delivered to alternative locations. This requires that they pass either across or into a specific membrane. This proposal aims to learn more about this important process using the bacterial cell membrane as a model system. The apparatus responsible for protein movement across membranes has been purified. Once prepared, various parts will then be labelled with chemical reagents that are able to report on their environment by the way that they interact with light. These probes will characterise the movements that the components make as they transport proteins across the membrane, which will aid our understanding of this reaction. New findings in this area will have implications in the understanding of protein secretion, cell biogenesis and development. Moreover, they will also help us understand other molecular machines and more general processes such as membrane transport. This information might be also exploited toward the development novel antibiotics.