13 ERA IB: Production of new bioactive compounds by plants and bacteria using new and improved halogenases

天然产物（由植物和微生物产生的复杂分子）表现出丰富的农业和医学重要活动。例如，生长素分子，这是从氨基酸色氨酸衍生，控制植物生长的速度。天然产品也具有巨大的药用价值。在过去的三十年中，超过60%的抗癌药物和超过70%的进入临床试验的抗生素是基于天然产物。关键的例子包括抗生素万古霉素（由微生物产生）和抗癌剂紫杉醇（由植物产生）。将卤素-氯或溴原子-引入天然产物中经常被证明可以提高生物活性和生物利用度。此外，氯或溴的掺入提供了可用于进一步衍生化产物的反应性柄，从而甚至进一步调节其生物活性。许多天然产物的固有复杂性使得它们及其类似物难以使用化学方法生产。因此，这些化合物的酶促合成的发展是非常有吸引力的。最近发现了一种叫做卤化酶的酶，它催化氯或溴进入天然产物。在这份提案中，我们描述了一个由五个学术合作伙伴和一个工业合作伙伴组成的财团，以开发和实施这些利用卤化酶的合成工艺。该提案描述了一种高度跨学科的方法：a）发现新的卤化酶B）工程化卤化酶以改变其特异性c）开发化学方法以在酶促安装后进一步衍生卤素d）评估产生的任何新化合物的结构和农用化学生物活性。我们设想，作为本提案中所开展工作的结果，我们将：a）拥有一套卤化酶，学术和工业科学家可以使用这些酶来生产各种各样的卤化化合物，这些卤化化合物具有小规模或大规模的广泛应用b）组装一个具有不寻常的卤化模式和来自卤素位点的化学衍生的新型“非天然天然产物”库b）与工业合作伙伴先正达合作，分析该化合物库的农业生物活性（例如筛选新农药

Natural products (complex molecules produced by plants and microorganisms) exhibit a wealth of agriculturally and medicinally significant activities. For example, auxin molecules, which are derived from the amino acid tryptophan, control how fast plants grow. Natural products also have tremendous medicinal value. Over the past three decades more than 60% of anticancer agents and over 70% of antibiotics entering clinical trials were based on natural products. Key examples include the antibiotic vancomycin (generated by a microbe) and the anticancer agent taxol (generated by a plant).The introduction of a halogen- a chlorine or bromine atom- into a natural product has frequently been demonstrated to improve bioactivity and bioavailability. Furthermore, the incorporation of chlorine or bromine provides a reactive handle that may be utilised to further derivatise the product, and thereby modulate its bioactivity even further. The inherent complexity of many natural products renders them and their analogues hard to produce using chemical methods. Therefore, development of enzymatic syntheses for these compounds is highly attractive. Enzymes called halogenases that catalyse the installation of chlorine or bromine into natural products have been recently discovered. In this proposal, we describe a consortium of five academic partners and one industrial partner to develop and implement these synthetic processes that utilise halogenases. The proposal describes a highly inter-disciplinary approach to:a) discover new halogenases b) engineer halogenases to change their specificity c) develop chemical methods to further derivatise the halogen after it has been enzymatically installed d) evaluate the structure and agrochemical bioactivity of any of the new compounds that are produced. We envision that as a result of the work performed in this proposal we will:a) have in hand a "suite" of halogenase enzymes that academic and industrial scientists can use to produce a wide range of halogenated compounds with a broad range of applications on a small or large scaleb) assemble a library of novel "unnatural natural products" with unusual halogenation patterns and chemical derivatisations from the halogen sitec) assay this library of compounds for biological activity for the agricultural industry (e.g. screen for new pesticides) in collaboration with Syngenta, the industrial partner