BIOSYNTHESIS OF ANTITUBERCULAR NONRIBOSOMAL PEPTIDES

描述(申请人提供)：除艾滋病外，结核病(TB)在全世界死于年轻人和中年人的人数超过任何其他疾病。此外，结核病是艾滋病毒/艾滋病患者发病和死亡的主要原因。虽然结核病通常被认为是一种困扰最贫穷国家的疾病，但耐多药结核病(MDR-TB)病例的迅速增加及其向工业化国家的传播使该疾病成为全球威胁。由于主要药物变得无效，必须使用更昂贵、通常效果较差、往往毒性更大的二线药物。因此，对新的抗结核药物的需求从未像现在这样强烈，但自推出最后一种新型抗结核药物以来，已经有30多年了。提高疗效、降低毒性和缩短疗程的进展将对世界卫生和医疗保健成本产生巨大影响。本申请描述了一种获取、利用和操纵肽生物合成基因的方法，该基因指导前体构建和组装后剪裁以创建新的抗结核多肽。目标是维霉素的类似物，维霉素是一种由醋酸链霉菌生产的多肽抗生素，也是一种二线抗结核药物，通常对多药耐药结核病有效。紫霉素具有稀有和独特的氨基酸，这些氨基酸对生物活性至关重要，但不能用于化学合成。该建议描述了导致这些新氨基酸的生化转化的研究，包括建议发生在多肽载体(PCP)蛋白结合物种上的反应。有人建议进行实验，通过靶向基因破坏和定向生物合成，通过外源添加或原位形成前体类似物来产生新的多肽。通过控制修饰并充分激活核心肽的酶也将形成新的化合物。成功地利用基因并破译与维霉素前体组装和剪裁有关的生化机制将产生有价值的信息，这些信息将被转化为新的分子工具，用于生产新的抗结核药物。从这些研究中获得的知识和方法将直接适用于扩大其他生物活性多肽家族的化学多样性。

DESCRIPTION (provided by applicant): Tuberculosis (TB) kills more young and middle-aged adults worldwide than any other disease with the exception of AIDS. Furthermore, TB is the leading cause of morbidity and mortality among the population living with HIV/AIDS. While TB is generally perceived as a disease afflicting the poorest countries, the rapid increase in cases of multidrug-resistant tuberculosis (MDR-TB) and its spread to industrialized nations makes the disease a global threat. As primary drugs are rendered ineffective, second-line agents that are more expensive, usually less effective and often more toxic must be used. Hence, the need for new anti-TB drugs has never been greater, yet it has been over 30 years since the introduction of the last novel antitubercular agent. Advances to improve potency, decrease toxicity, and shorten the duration of therapy would have an enormous impact on world health and healthcare costs. This application describes an approach to access, utilize and manipulate peptide biosynthesis genes that direct precursor construction and post-assembly tailoring to create novel antitubercular peptides. The targets are analogs of viomycin, a peptide antibiotic produced by Streptomyces vinaceus and a second-line antitubercular agent that is often effective against MDR-TB. Viomycin possesses rare and unique amino acids that are crucial for biological activity but are not available for chemical synthesis. The proposal describes studies on the biochemical transformations leading to these novel amino acids, including reactions proposed to occur on peptidyl carrier (PCP) protein-bound species. Experiments are proposed to generate new peptides through targeted gene disruption and directed biosynthesis with precursor analogs added exogenously or formed in situ. Novel compounds will also be formed by controlling enzymes that decorate and fully activate the core peptide. Successfully harnessing the genes and deciphering the biochemical mechanisms involved in viomycin precursor assembly and tailoring will yield valuable information that will be translated into novel molecular tools for generating new antitubercular agents. The knowledge and methods that arise from these studies will be directly applicable to expanding the chemical diversity in other families of bioactive peptides.