The Promiscuity of EpoC Towards Polymer Bound Substrates

描述（由申请人提供）： 小分子多肽、聚酮化合物和聚酮/多肽杂合天然产物具有生物活性强、生物合成模块化等特点。这些化合物通常由模块聚酮合酶（PKS）、非核糖体肽合成酶（NRPS）和杂合NRPS/PKS酶产生。迄今为止，对杂合NRPS/PKS酶的NRPS/PKS界面的研究有限。该建议旨在通过探索epoC的酮合酶（KS）结构域对固相结合肽底物的混杂性来研究epothilone合酶的NRPS/PKS界面。EpoC位于埃博霉素合酶的杂合NRPS/PKS界面，由于埃博霉素的药学意义和关于其生物合成的大量工作，因此选择EpoC用于本研究。通过将该技术应用于肽底物库，将开发对epoC的底物特异性的详细理解，从而打开了重新设计埃坡霉素生物合成以产生新型埃坡霉素衍生物的大门。此外，通过将epoC融合到另外的PKS模块，可以获得杂合多肽/聚酮化合物分子的组合文库用于通过半生物合成的药物发现。

DESCRIPTION (provided by applicant): Small molecule peptide, polyketide and hybrid polyketide/polypeptide natural products are characterized by their potent biological activities and modular biosyntheses. These compounds typically are generated by modular polyketide synthase (PKS), nonribosomal peptide synthetase (NRPS) and hybrid NRPS/PKS enzymes. To date, there has been limited study of the NRPS/PKS interface of hybrid NRPS/PKS enzymes. This proposal seeks to examine the NRPS/PKS interface of epothilone synthase by exploring the promiscuity of the ketosynthase (KS) domain of epoC towards solid phase bound peptide substrates. EpoC, which sits at the hybrid NRPS/PKS interface of epothilone synthase, was chosen for this study because of the pharmaceutical significance of the epothilones and the extensive body of work regarding their biosynthesis. By applying this technology to libraries of peptide substrates a detailed understanding of the substrate specificity of epoC will be developed, opening the door to reengineering epothilone biosynthesis to generation of novel epothilone derivatives. Also, by fusing epoC to additional PKS modules, combinatorial libraries of hybrid polypeptide/polyketide molecules can be accessed for drug discovery by semibiosynthesis.