Chemoenzymatic analysis of bryostatin biosynthesis

描述(申请人提供)：Bryostatins是从海洋苔藓虫Bugula neritina中分离出来的聚酮类次生代谢物。Bryostatin 1是一种非常有前途的抗癌药物，目前正在进行二期临床试验。不幸的是，Bryostatin在B.neritina中的浓度非常低，到目前为止，还没有化学合成替代品，需要收获大量的动物来获得足够数量的Bryostatin用于生物测试。最近的研究表明，苔藓素类化合物是由细菌内共生菌Endobugula sertula产生的，但培养这种微生物的尝试并不成功。因此，最新的研究工作导致从共生体丰富的DMA中鉴定出一个聚酮合成酶(PKS)基因簇，该基因簇可能与苔藓抑素的生物合成有关。然而，由于该生物体不能被培养，因此无法进行突变和互补实验来验证该簇是否产生Bryostatin。在这个项目中，我建议使用纯化的假定的Bryostatin PKS模块进行体外研究，以确定该基因簇是否确实对Bryostatin的产生负责。这项研究可能导致异源宿主产生Bryostatin。

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.