Biosynthesis of Pyrrolo[1,4]benzodiazepines, potent antitumor antibiotics

描述（由申请人提供）：次生代谢物通常由生物体产生，作为防御机制的一部分或促进繁殖。次级代谢物的化学多样性反映了生物合成途径中存在的酶促反应的多样性。因此，这些途径是令人兴奋的新颖转化和前所未有的酶的持续而丰富的来源。此外，通过阐明生物合成途径获得的遗传和酶学知识可用于生产化学上不同的次级代谢产物。吡咯并[1,4]苯二氮卓类药物是放线菌中发现的一类强效抗肿瘤抗生素，是序列选择性 DNA 烷化剂。 SJG-136治疗转移性或不可切除实体瘤的一期人体临床试验于2004年开始。本提案将使用微生物学、分子生物学和酶学技术来阐明吡咯并[1,4]苯二平生产的生物化学基础。具体来说，我们建议 1) 鉴定茅霉素和西伯霉素的生物合成基因簇，2) 产生新型糖基化 PBD 和 PBD 二聚体，3) 表征生物合成途径中存在的独特酶促转化。公共 健康相关性 吡咯并苯二氮卓类药物 (PBD) 是细菌天然产生的化合物，具有有效的抗肿瘤特性。 PBD 具有显着的广谱活性和对抗多种癌症的功效，这鼓励了新的 PBD 的开发。例如，SJG-136目前正在进行针对转移性和不可切除实体瘤的I期临床试验。我们提议研究大自然如何合成这些化合物。如此获得的遗传和酶学知识可用于生产这些化合物的新类似物。本提案讨论了此类应​​用的示例。

DESCRIPTION (provided by applicant): Secondary metabolites are usually produced by an organism as part of a defense mechanism or to facilitate reproduction. The chemical diversity of secondary metabolites mirrors the variety of enzymatic reactions present in the biosynthetic pathways. Therefore, these pathways are a constant and rich source of exciting novel transformations and unprecedented enzymes. In addition, the genetic and enzymatic knowledge acquired by elucidating the biosynthetic pathways can be exploited for the production of chemically varied secondary metabolites. Pyrrolo[1,4]benzodiazepines, a class of potent antitumor antibiotics found in actinomycetes, are sequence selective DNA alkylating agents. Phase 1 human clinical trials of SJG-136 for the treatment of metastatic or unresectable solid tumors were started in 2004. Microbiology, molecular biology and enzymological techniques will be used in this proposal to elucidate the biochemistry underlying pyrrolo[1,4]benzodiapines' production. Specifically, we propose to 1) identify the biosynthetic gene clusters for tomaymycin and sibiromycin, 2) produce novel glycosylated PBDs and PBD dimers, and 3) characterize the unique enzymatic transformations present in the biosynthetic pathway. PUBLIC HEALTH RELEVANCE Pyrrolobenzodiazepines (PBDs) are compounds naturally produced by bacteria with potent antitumor properties. PBDs' remarkable broad spectrum of activities and effectiveness against a wide variety of cancers encourages the development of new PBDs. For instance, SJG-136 is currently in phase I clinical trials against metastatic and unresectable solid tumors. We are proposing to study how nature carries out the synthesis of these compounds. The genetic and enzymological knowledge so obtained can then be used for production of new analogs of these compounds. Examples of such application are discussed in this proposal.