Unveiling the Enigmatic Biosynthetic Machinery of the Azinomycins

阿奇霉素是针对DNA(所有生命的遗传基础)的微生物的天然产物，具有抗肿瘤和抗细菌活性。化学部的美国国家科学基金会生命过程化学项目资助了德克萨斯农工大学的Coran M.H.Watanabe博士，以确定大自然是如何构建滋生菌素的。这些研究描述了蛋白质的功能和结构，这些蛋白质催化独特的生化步骤，这些步骤涉及产生对其生物活性重要的氮菌素的化学特征。从这项研究中获得的知识为未来的基因工程铺平了道路，以便在肿瘤细胞内合成氮霉素来治疗癌症。该项目使研究生、本科生和博士后实习生能够发展化学生物学和生物技术方面的广泛技能。此外，这项研究被整合到一门课程中，教授生物活性物质如何从环境中衍生出来。这门课的学生收集土壤样本，然后对其进行分析，以确定是否有显示出抗生素活性的天然产品。此外，当地的小学生、初中生和高中生通过量身定制的讲座、演示和实验室体验，了解他们生活中的天然产品和微生物。最后，只要有机会，渡边博士就会参加美国癌症协会生命接力赛等活动，向公众介绍癌症研究以及从事研究的教职员工的日常工作相关活动。奇菌素是建筑上令人着迷的天然产品。该天然产物通过环烷酸酯、环氧化物、烯醇和氮杂二环体系进行了密集的官能化。该分子的基本骨架是通过聚酮合成酶/非核糖体肽合成酶(PKS/NRPS)途径产生的，而氮杂环并[1，2-a]吡咯烷部分是生物碱衍生的。从酶学的角度来看，这种天然产物代表了有待挖掘的不寻常生物合成转化的宝库，并为化学酶/合成生物学的努力铺平了道路。该项目的目标是从功能上重建和表征阿奇霉素生物合成途径的酶，并开始开发操纵该途径的方法。实现这些目标的目标包括1)表征氮菌素的环甲酸酯部分的生物合成的酶机制，并分析该杂菌的结构和功能相关类似物的结构-活性关系，2)探索环氧化物单元的化学，以及3)氮杂环部分的生物合成的酶的功能表征。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Azinomycins are natural products from microbes that target DNA (the genetic basis of all life) and have demonstrated anti-tumor and anti-bacterial activities. The National Science Foundation, Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Coran M. H. Watanabe from Texas A&M University to determine how nature constructs the azinomycins. These studies characterize the functions and structures of the proteins that catalyze the unique biochemical steps involved in generating the chemical features of the azinomycins that are important for their biological activity. The knowledge gained from this research paves the way for future engineering of genes to synthesize azinomycins within a tumor cell to treat cancer. This project enables graduate and undergraduate students, and postdoctoral trainees to develop broad skills in chemical biology and biotechnology. Moreover, this research is integrated into a class that teaches how bioactive agents are derived from the environment. Students in this class collect soil samples, which are then assayed for natural products that show antibiotic activity. In addition, local elementary, middle, and high school students learn about natural products and microbes in their lives through tailored lectures, demonstrations, and laboratory experiences. Finally, as opportunities arise, Dr. Watanabe participates in events such as the American Cancer Society Relay for Life Events to inform the general public about cancer research and the daily work-related activities of a research active faculty member. The azinomycins are architecturally fascinating natural products. The natural product is densely functionalized with a naphtoate, epoxide, enol, and azabicyclic ring system. The basic skeletal framework of the molecule is generated through a polyketide synthase/nonribosomal peptide synthetase (PKS/NRPS) pathway, while the aziridino[1,2-a]pyrollidine moiety is alkaloid derived. From an enzymological perspective, this natural product represents a treasure trove of unusual biosynthetic transformations to be mined and paves the way for chemoenzymatic/synthetic biology efforts. The goals of this project are to functionally reconstitute and characterize enzymes of the azinomycin biosynthetic pathway, and begin to develop ways to manipulate the pathway. The objectives towards these goals include 1) characterizing the enzymatic mechanism for biosynthesis of the naphthoate moiety of the azinomycins and analyze the structure-activity relationships of structurally and functionally related analogs of this mioety, 2) exploring the chemistry of the epoxide unit, and 3) functionally characterizing the enzymes for the biosynthesis of the azabicycle moiety.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.