GENERATION OF KETOLIDES BY COMBINATORIAL BIOSYNTHESIS

该项目的总体商业目标是利用组合生物合成技术创建酮内酯抗感染新药。其具体目标是：L)在淡色链霉菌中建立一个通用的质粒-宿主表达系统，通过该系统可以快速、系统地产生吡克罗霉素类似物；以及2)通过创建将吡克罗霉素聚酮合成酶(PIKA)和头孢霉素C非核糖体多肽合成酶结构域相结合的‘杂交生物合成途径’来产生酮内酯。拟议计划的一个关键方面涉及提炼一种多功能表达系统，用于复杂聚酮天然产物的工程生物合成。这将提供酮内酯分子的聚酮和氨基糖衍生部分的以质粒或染色体为导向的生物合成。这套通用的分子遗传工具的开发将使大量酮内酯结构的快速产生成为可能，从而引领新的抗感染药物的发现。随着我们分子遗传工具的发展，将产生两种特定的杂交生物合成途径，它们将引入多功能的分子手柄来创建酮内酯抗生素。我们期望这项技术将提供新酮内酯分子和结构模板的快速来源，用于在抗菌检测系统中进行分析，并用于使用组合化学或药物化学方法的进一步开发。拟议的商业应用：拟议的研究涉及开发一项技术并将其付诸实践，该技术将为产生具有抗耐药病原菌活性的新型药物提供快速的新化学实体。

The overall commercial aim of this project is to create new ketolide antiinfective agents using combinatorial biosynthesis technologies. The specific aims are: l) to develop a versatile plasmid-host expression system in Streptomyces venezuelae through which pikromycin analogues can be generated rapidly and systematically; and 2) generate novel ketolides by creating a 'hybrid biosynthetic pathway that combines the pikromycin polyketide synthase (PikA) with a cephamycin C non-ribosomal peptide synthetase domain. A key aspect of the proposed program involves refining a versatile expression system for engineered biosynthesis of complex polyketide natural products. This will provide plasmid- or chromosome-directed biosynthesis of the polyketide derived and aminosugar derived portions of the ketolide molecules. The development of this versatile set of molecular genetic tools will enable rapid generation of large numbers of ketolide structures for lead discovery of new antiinfective agents. Concurrent to the development of our molecular genetic tools, two specific hybrid biosynthetic pathways will be generated that introduce versatile molecular handles for creation of novel ketolide antibiotics. We expect this technology will provide a rapid source of novel ketolide molecules and structural templates for analysis in antimicrobial assay systems, and for further development using combinatorial chemistry or medicinal chemistry approaches. PROPOSED COMMERCIAL APPLICATIONS: The proposed research involves the development and reduction to practice of a technology that will provide rapid creation of new chemical entities for generation of novel pharmaceuticals with activity against drug-resistant pathogenic bacteria.