Analysis of the of the interaction between the SecY protein translocation complex and its substrate pre-protein

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。这些膜为水和亲水溶质提供了屏障。它们的作用是将生物反应与外界隔离开来，并提供分离电荷、相互交流和结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、发展和维持细胞复杂结构和生物化学的能力。物质必须通过脂质膜在外部和不同的隔室之间进行交换，这就产生了小分子和大分子的运输问题。蛋白质是根据细胞质中每个基因的遗传密码合成的大型氨基酸聚合物。为了执行其特定的角色，他们中的许多人需要明确目标并交付到替代位置。这要求它们穿过或进入特定的膜。本课题旨在利用细菌细胞膜作为模型系统，进一步了解这一重要过程。负责蛋白质跨膜运动的装置已被纯化。这个蛋白质通道和它的多肽底物的相互作用将被我们使用的各种生化和生物物理方法所研究。这一领域的新发现将对蛋白质易位的理解产生影响。此外，它们还将帮助我们理解生物学中涉及蛋白质复合物与多肽相互作用的许多其他重要问题。

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 and combine 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 specifically targeted and 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. The interaction of this protein channel and its polypeptide substrate will be studies using a variety of biochemical and biophysical approaches that we have at our disposal. New findings in this area will have implications in the understanding of protein translocation. Moreover, they will also help us understand numerous other important problems in biology that involve the interaction of protein complexes with polypeptides.