Synthetic Biology Pathways to Isoquinoline Alkaloids

几千年来，人类一直在使用植物和植物中的药用化合物来治疗疼痛、疾病、感染，也用于娱乐目的。许多这些植物衍生的化合物也被用于现代药物的使用，例如用于缓解疼痛的吗啡和可待因，用于提高心率和治疗肠易激综合征的阿托品，用于治疗癌症的长春花碱和用于治疗疟疾的奎宁。已知的生物碱化学结构超过14000种，它们代表着丰富的潜在生物活性。然而，这些生物碱的数量很少，或者存在于稀有植物中，或者只生长在世界上难以获得的部分地区。植物合成生物碱的途径通常很长，有许多生物合成步骤。有一些关键的中间化合物是许多植物生物碱途径共同的，生物碱结构的复杂性来自于不同植物在途径中不同的后期步骤。如果能够以更可控的方式制造这些关键的中间生物碱化合物，并能够利用酶或化学方法修饰这些生物碱的结构，那将是非常有益的。通过这种方式，可以发现新的生物活性药物。几种生物碱的合成途径已经开始确定，但一些更复杂的生物碱的许多合成步骤仍然未知。在过去的几年里，研究人员已经开始分离酶（和它们的基因），用于合成某些生物碱的一些关键步骤。其中一些酶执行非常重要的步骤，例如将源自简单氨基酸的相当简单的化合物连接在一起。我们打算利用全基因合成、合成生物学和途径设计技术来制造这些关键的生物碱合成酶，并将它们放入实验室细菌中。通过这种方式，我们可以结合不同的植物酶和细菌酶，建立合成途径，创造新的化合物，可以筛选有用的药用活性。通过在细菌中拥有这些途径，我们将能够使用可再生资源以可再生的方式产生它们，而不依赖于困难或稀有植物的生长。此外，不需要使用目前用于合成这种异喹啉的具有高度环境影响的方法进行广泛的化学转化。

For thousands of years mankind has been using plants and medicinal compounds from plants for treating pain, diseases, infections and also for recreational purposes. Many of these plant derived compounds have also found their way into modern drug use for example morphine and codeine for pain relief, atropine to increase heart rate and for irritable bowel syndrome, vinblastine to treat cancers and quinine for malaria. There are over 14,000 alkaloid chemical structures known and these represent a wealth of potential biological activity. However many of these alkaloids occur in small amounts or in plants that are rare or only grow in parts of the world that are difficult to access. The pathways that plants use to synthesise alkaloids are often long with many biosynthetic steps. There are some key intermediate compounds that are common to many plant alkaloid pathways and the complexity of alkaloid structures comes from the different later steps in the pathways that different plants have. It would be of great benefit to be able to make some of these key intermediate alkaloid compounds in a more controlled way and to be able to modify these alkaloid structures using enzymes or chemistry. In this way novel biologically active drugs could be found. The pathways for the synthesis of several alkaloids have begun to be determined but many of the steps for some of the more complex alkaloids are still unknown. In the last few years researchers have begun to isolate the enzymes (and their genes) for some of the key steps in the synthesis of some alkaloids. Some of these enzymes carry out very important steps such as the joining together of rather simple compounds derived from simple amino acids. We intend to use the techniques of whole gene synthesis, synthetic biology and pathway design to make some of these key alkaloid synthesising enzymes and put them into a laboratory bacterium. In this way we can combine different plant based and bacterial enzymes and build synthetic pathways for the creation of new chemical compounds that could be screened for useful medicinal activities. By having the pathways in bacteria we would be able to generate them in a reproducible way using a renewable resource and not be dependant on the growth of difficult or rare plants. In addition, extensive chemical transformations using methods with high environmental impact would not be required which are currently used to synthesise such isoquinolines.