EXPORT OF PROTEINS IN ESCHERICHIA COLI

原核系统中蛋白质输出机制的阐明 将提供一个现象的相关信息， 生物过程，如细胞器的分泌和生物发生。 此外，最近开发的重组DNA技术使 可能生产医学上重要的真核蛋白质， 细菌 如果我们理解了这些原则， 细菌出口的详细信息。 从出口研究中得出的数据是 目前根据信号假设或触发器来组织 假说. 我们提出的实验旨在区分 这些假设的主要特征。 我们将决定在什么时候 合成新生链最初与膜结合，何时以及通过什么 它们被易位和蛋白水解加工， 表征质子动力参与输出。 我们将 启动革兰氏阳性菌输出调查并比较 这一发现与已知的革兰氏阴性菌的输出有关。 拟议的研究涉及分子生物学技术， 生物化学如体内脉冲标记，体外蛋白质合成， 膜分离和分级分离以及通过 高效液相色谱法 拟议的工作应导致 在理解特定通道方面取得了重大进展， 蛋白质通过生物膜。

Elucidation of the mechanism of export of protein in prokaryotic systems will provide information relevant to a phenomenon central to many biological process such as secretion and biogenesis of organelles. Furthermore, the recently developed recombinant DNA technology has made possible the production of medically important eukaryotic proteins in bacteria. Such production can be made most efficient if we understand the details of export in bacteria. Data derived from studies on export is currently organized in terms of either the signal hypothesis or the trigger hypothesis. We propose experiments designed to distinguish between the major features of these hypotheses. We shall determine at what point in synthesis nascent chains initially bind to the membrane, when and by what mechanism they are translocated and proteolytically processed and further characterize the involvement of proton motive force in export. We shall initiate investigations of export in a gram positive bacterium and compare the findings with what is known about export in gram negative bacteria. The proposed research involves techniques of molecular biology and biochemistry such as in vivo pulse-labeling, in vitro protein synthesis, membrane isolation and fractionation and analysis of proteolytic digests by high performance liquid chromatography. The work proposed should result in significant progress toward the understanding of the specific passage of protein through biological membranes.