ENGINEERED BIOSYNTHESIS OF NOVEL KETOLIDE ANTIBIOTICS

酮类抗生素最近引起了极大的兴趣，因为它们对许多大环内酯类耐药微生物，特别是葡萄球菌和肠球菌具有活性。本研究计划的总体目标是利用组合生物合成和生化途径工程来生产新型功能化酮内酯类抗生素。弗吉尼亚联邦大学（VCU）和中西部分子公司（位于明尼苏达州明尼阿波利斯市的一家小型企业）的两项技术的组合将用于实现这一目标。 VCU技术包括能够在体内产生用于聚酮化合物生物合成的一系列新型羟基化和去饱和环己烷羧酸起始单元的基因盒。中西部分子技术是一套多功能的匹克罗霉素聚酮生物合成酶，用于生产14元酮内酯类抗生素，可通过工程改造接受这些新型起始单元。拟议的商业应用：酮内酯有望作为红霉素耐药性细菌病原体增加的解决方案，包括化脓性链球菌、肺炎链球菌、金黄色葡萄球菌和一些肠球菌。许多大型制药公司都有半合成酮内酯，目前正处于II期临床试验阶段。拟议的研究将使用一种基于遗传的生物合成技术与聚酮合酶基因工程相结合，以经济可行的方式产生一系列其他技术无法获得的新型酮内酯。

Ketolide antibiotics have recently attracted significant interest because they have activity against a number ofmacrolide-resistant microorganisms, in particular staphylococci and enterococci. The overall objective of this research program is to use combinatorial biosynthesis and biochemical pathway engineering to produce novel functionalized ketolide antibiotics. A combination of two technologies belonging to Virginia Commonwealth University (VCU), and Midwest Molecular (a small business located in Minneapolis, Minnesota) will be used to achieve this goal. The VCU technology comprises a gene cassette capable of in vivo generation of a range of novel hydroxylated and desaturated cyclohexanecarboxylic acid starter units for polyketide biosynthesis. The Midwest Molecular technology is a set of versatile pikromycin polyketide biosynthetic enzymes for production of 14-membered ketolide antibiotics that can be engineered to accept these novel starter units. PROPOSED COMMERCIAL APPLICATIONS: Ketolides hold promise as a solution to the increase in erythromycin- resistant bacterial pathogens, including Streptococcus pyogenes, Streptococcus pneumoniae, Staphylococcus aureus and some enterococci. Numerous large pharmaceutical companies have semisynthetic ketolides which are now in phase II clinical trials. The proposed research will use a genetic-based precursor-directed biosynthetic technology in combination with polyketide synthase genetic engineering, to generate in an economically viable manner a range of novel ketolides not available from other technologies.