Novel Approaches to Accessing Secondary Metabolites

描述（由申请人提供）：该项目的总体目标是开发针对鼠疫耶尔森氏菌的新型治疗剂，鼠疫耶尔森氏菌是鼠疫的病原体，也是最危险的潜在生物武器之一。在这个探索性的项目中，我们将开发新的方法来获得以前无法从放线菌的次级代谢产物。这些生物体传统上是抗生素的主要来源。最近的两个充分研究的链霉菌物种的全基因组测序揭示了潜在的抗生素合成的额外模块。这与文献中先前的数据一致，表明大多数抗生素在体外生长条件下不表达。可以合理地假设抗生素是在自然环境中表达的，在那里它们为生产生物体提供了竞争优势。我们的总体方法是模仿自然环境来诱导抗生素的生产。本计画将发展两种启发式方法。根据我们的初步数据，有一种特殊类型的化合物可以模拟环境的一个关键方面，并作为抗生素诱导剂。将用一组已知的放线菌对这些物质引起以前未知的抗生素产生的能力进行详细的检查。抗生素诱导的另一种方法将基于在我们先前用于生长“不可培养的”微生物的扩散室中在其天然环境（土壤）中培养微生物（Kaeberlein，T.，刘易斯，K.，和Epstein，S. S.（2002）Science 296：1127-1129）。使用诱导从已知生物体中发现具有抗微生物活性的新化合物将构成所提出方法的原理证明。我们开发的方法将允许在第二阶段进行大规模筛选和验证，这将导致新的抗Y的开发。鼠疫疗法

DESCRIPTION (provided by applicant): The overall goal of this project is to develop novel therapeutic agents against Yersinia pestis, the causative agent of plague and one of the most dangerous potential bioweapons. In this exploratory project, we will develop novel approaches to obtain previously inaccessible secondary metabolites from actinomycetes. These organisms have traditionally served as the main source for antibiotics. Recent whole genome sequencing of two well-studied streptomycete species revealed potential additional modules for synthesis of antibiotics. This agrees well with previous data from the literature indicating that the majority of antibiotics are not expressed under in vitro growth conditions. It is reasonable to assume that antibiotics are expressed in a natural environment, where they provide a competitive advantage to the producing organism. Our overall approach is to emulate the natural environment to elicit production of antibiotics. We will develop two elicitation methods in this project. According to our preliminary data, there is a particular type of compounds that emulate a critical aspect of the environment and act as antibiotic elicitors. A detailed examination of the ability of these substances to elicit production of previously unknown antibiotics will be performed with a panel of known actinomycetes. Another method of antibiotic elicitation will be based on culturing microorganisms in their natural environment, soil, in a diffusion chamber that we have previously used to grow "unculturable" microorganisms (Kaeberlein, T., Lewis, K., and Epstein, S.S. (2002) Science 296:1127-1129). Finding new compounds with antimicrobial activity from known organisms using elicitation will constitute proof of principle for the proposed approach. The methods we develop will allow for large-scale screening and validation in Phase II which will lead to the development of a new anti-Y. pestis therapy.