Chemoenzymatic analysis of bryostatin biosynthesis

描述（由申请人提供）：苔藓虫素是从海洋苔藓虫Bugula neritina中分离出来的聚酮类次级代谢物。苔藓虫素1是一种非常有前景的抗癌药物，目前正在进行II期临床试验。不幸的是，褐藻中的苔藓虫素浓度非常低，迄今为止，没有化学合成替代品，需要大量收获动物以获得足够数量的苔藓虫素进行生物测试。最近的研究表明苔藓抑素是由细菌内共生体，内管菌sertula产生的，但试图培养这种微生物尚未成功。因此，最新的研究工作已经导致从共生体富集的DMA中鉴定出可能负责苔藓抑素生物合成的聚酮合成酶（PKS）基因簇。然而，由于该生物无法培养，因此无法进行验证该簇是否产生苔藓虫素的突变和互补实验。在这个项目中，我建议使用纯化的假定苔藓虫素PKS模块进行体外研究，以确定该基因簇是否实际上负责苔藓虫素的产生。该研究可能导致异源寄主产生苔藓虫素。

DESCRIPTION (provided by applicant): Bryostatins are polyketide secondary metabolites isolated from the marine bryozoan Bugula neritina. Bryostatin 1 is a very promising anti-cancer drug, and is currently undergoing Phase II clinical trials. Unfortunately, bryostatin concentrations in B. neritina are very low and, to date, there are no chemical synthetic alternatives, requiring the harvest of large amounts of the animal to obtain sufficient quantities of bryostatin for biotesting. Recent research has revealed that the bryostatins are produced by the bacterial endosymbiont, Endobugula sertula, but attempts to culture the microbe have not been successful. Consequently, the latest research effort has resulted in the identification of a polyketide synthase (PKS) gene cluster from symbiont-enriched DMA that may be responsible for bryostatin biosynthesis. However, as the organism cannot be cultured, mutation and complementation experiments that can verify whether this cluster produces bryostatin cannot be conducted. In this project, I propose to use in vitro studies with purified putative bryostatin PKS modules to determine whether this gene cluster is in fact responsible for the production of bryostatin. This research may lead to production of bryostatin by a heterologous host.