天然产物生物合成与抗肿瘤药物合成生物学研究

结构复杂多样的天然产物是现代药物的重要组成部分和新药发现的重要源泉.天然产物的生物合成研究,是从基因和蛋白水平阐明天然产物的合成途径,通过酶催化的化学反应将基因与化合物的结构单元建立一种对应关系,从而理解自然界神奇的化学合成、生物拮抗及生理调控过程.天然产物的合成生物学研究核心是通过在发酵友好、高效的微生物中设计、构建目标化合物的生物合成途径,经系统地调控和优化重组微生物,从而发酵生产来源稀缺的天然产物类药物、前体或新化合物.本文结合相关领域的进展,对本研究组近年来关于抗肿瘤天然产物生物合成及抗癌药物合成生物学的工作进行系统的介绍.     

植物来源药用天然产物的合成生物学研究进展

大多数药用天然产物在植物中含量低微,提取分离困难;而且这些化合物一般结构复杂,化学合成难度大,还容易造成环境污染。基于合成生物学技术获得药用天然产物具有绿色环保和可持续发展等优点。文中以药用萜类化合物人参皂苷、紫杉醇、青蒿素、丹参酮,生物碱类化合物长春新碱、吗啡以及黄酮类化合物灯盏花素为例,总结了植物来源药用萜类、生物碱类和黄酮类化合物的生物合成途径及合成生物学研究进展,介绍了药用天然产物合成生物学研究的关键技术与方法,并展望了合成生物学技术在药用天然产物研究与开发方面的应用前景。     

天然产物合成生物学体系的优化策略

天然产物是新药研发的重要源泉。天然产物合成生物学通过设计、重构目标化合物的高效生物合成途径,借助宿主改造,利用发酵生产目标化合物,可以有效弥补有机合成化学在复杂天然产物类药物生产方面的不足。虽然合成生物学已经取得了一些进展,但是通过合成生物学技术使目标产物的产量达到工业化生产水平依然是一项非常具有挑战性的任务。综述了天然产物合成生物学体系的优化策略,通过综合运用单个元件、外源代谢途径、底盘系统和发酵条件的优化技术,可以实现生物合成系统的最优化,最大化目标产物的产量,为来源稀缺的复杂天然产物的开发提供持续、稳定、经济的原料供给,推动天然产物类新药的研发。     

戊二酰亚胺类天然产物生物合成研究进展

微生物天然产物是天然药物的重要组成部分,而天然产物的良好生物活性很大程度上取决于发挥药效的结构基团。这些特殊药效基团的生物合成,通常是利用小分子羧酸、氨基酸等结构简单的初级代谢产物,经过复杂的生物化学过程,最终合成结构复杂活性多样的天然产物。戊二酰亚胺类天然产物是一类重要的细菌来源天然产物,它们具有良好的生物活性,是潜在的先导化合物,部分化合物已被开发成分子探针。本文综述了近年来微生物来源的戊二酰亚胺类天然产物及其生物合成研究,包括Iso-Migrastatin、Lactimidomyin、Cycloheximide、Streptimidone、Gladiostatin、Sesbanimide等,对戊二酰亚胺类天然产物的生物合成研究,将有效促进通过基因组挖掘策略寻找新型戊二酰亚胺类天然产物。     

合成生物学与天然产物开发

天然产物依然是临床用药的重要来源。合成生物学的诞生为天然产物的开发提供了全新的机遇,传统的微生物药物、植物天然产物等研究领域都因合成生物学而获得新生。重点介绍了合成生物学在天然产物开发中的应用,包括新化合物及其生物合成元件的筛选,基于理性设计的天然产物异源生物合成,人工底盘细胞的系统优化等。     

天然药物研究中的合成生物学

天然产物一直是药物分子设计和开发过程中的重要灵感来源之一,源自天然产物的临床用药目前也占据着难以替代的地位.但是大多数天然来源的药物分子结构复杂、分离困难,利用传统的合成化学和天然产物化学方法难以满足日益增长的市场需求.天然产物在其产生物种中一定对应着一个由若干功能各异的基因元件所构成的生物合成基因群,或成簇分布或离散分布.合成生物学则旨在通过对不同基因元件的改造、组合、拼装而得到新的生物途径和体系.本文主要将针对合成生物学在天然药物研究中的应用进行总结和展望,并从基因元件以及合成生物学的角度重新认识和理解天然产物的生物合成.     

植物底盘:天然产物合成生物学研究的新热点

天然产物广泛地存在于植物体内,是药物、食品添加剂和新型生物燃料等开发的主要来源,具有重要的商业价值,该类化合物也一直是合成生物学研究的热点之一。随着研究的深入,近年来以植物为底盘的天然产物研究日益兴起。本文中,笔者综述了近年来以植物为底盘的天然产物合成生物学研究的进展,包括该类代谢物代谢途径的解析、以植物为底盘的遗传操作技术和方法等,为相关研究者提供参考。     

微生物来源天然产物中的β-甲基色氨酸单元及其生物合成研究进展

微生物在次级代谢过程中通常会产生结构复杂、活性多样的天然产物。这些天然产物是新药发展的基础,亦可作为先导化合物或重要的药效基团用于药物研发。结构多样的氨基酸单元是参与合成复杂多样天然产物的重要前体。天然产物中的β-甲基氨基酸单元不仅可以赋予其生物活性,还能增强其生物稳定性而不被肽酶水解。本文综述了含有β-甲基氨基酸单元的天然产物,尤其对含有β-甲基色氨酸单元的天然产物生物合成途径进行了阐释。对β-甲基色氨酸单元生物合成途径的理解结合基因组数据有助于进行新结构天然产物的挖掘,并为运用代谢科学理念和合成生物学技术开发含有该单元的新化合物提供理论基础和可操作遗传元件。     

真菌天然产物异源生产研究进展

真菌天然产物是天然药物的重要来源之一,大规模真菌基因组序列测序的完成表明真菌具有产生丰富的次级代谢产物的潜能。然而,许多真菌或生长缓慢,或不适宜在实验室条件下培养,或难以进行遗传操作,或化合物产量极低等,这些因素导致大量有价值的真菌天然产物无法获得。利用异源表达系统对真菌天然产物进行生产是发现新天然产物及解析其生物合成途径的有效手段,并为定向的以合成生物学的手段去合成重要活性分子奠定基础。本文对目前用于真菌天然产物生产的各种异源表达系统进行了综述,并结合最新的DNA组装技术展望了异源表达系统在真菌天然产物研究中的应用价值和前景。     

微生物来源天然产物中的β-甲基色氨酸单元及其生物合成研究进展

微生物在次级代谢过程中通常会产生结构复杂、活性多样的天然产物。这些天然产物是新药发展的基础,亦可作为先导化合物或重要的药效基团用于药物研发。结构多样的氨基酸单元是参与合成复杂多样天然产物的重要前体。天然产物中的β-甲基氨基酸单元不仅可以赋予其生物活性,还能增强其生物稳定性而不被肽酶水解。本文综述了含有β-甲基氨基酸单元的天然产物,尤其对含有β-甲基色氨酸单元的天然产物生物合成途径进行了阐释。对β-甲基色氨酸单元生物合成途径的理解结合基因组数据有助于进行新结构天然产物的挖掘,并为运用代谢科学理念和合成生物学技术开发含有该单元的新化合物提供理论基础和可操作遗传元件。     

Production of isoprenoid pharmaceuticals by engineered microbes

Throughout human history, natural products have been the foundation for the discovery and development of therapeutics used to treat diseases ranging from cardiovascular disease to cancer. Their chemical diversity and complexity have provided structural scaffolds for small-molecule drugs and have consistently served as inspiration for medicinal design. However, the chemical complexity of natural products also presents one of the main roadblocks for production of these pharmaceuticals on an industrial scale. Chemical synthesis of natural products is often difficult and expensive, and isolation from their natural sources is also typically low yielding. Synthetic biology and metabolic engineering offer an alternative approach that is becoming more accessible as the tools for engineering microbes are further developed. By reconstructing heterologous metabolic pathways in genetically tractable host organisms, complex natural products can be produced from inexpensive sugar starting materials through large-scale fermentation processes. In this Perspective, we discuss ongoing research aimed toward the production of terpenoid natural products in genetically engineered Escherichia coli and Saccharomyces cerevisiae.     

Genetic and metabolic engineering of microorganisms for the development of new flavor compounds from terpenic substrates

Throughout human history, natural products have been the basis for the discovery and development of therapeutics, cosmetic and food compounds used in industry. Many compounds found in natural organisms are rather difficult to chemically synthesize and to extract in large amounts, and in this respect, genetic and metabolic engineering are playing an increasingly important role in the production of these compounds, such as new terpenes and terpenoids, which may potentially be used to create aromas in industry. Terpenes belong to the largest class of natural compounds, are produced by all living organisms and play a fundamental role in human nutrition, cosmetics and medicine. Recent advances in systems biology and synthetic biology are allowing us to perform metabolic engineering at the whole-cell level, thus enabling the optimal design of microorganisms for the efficient production of drugs, cosmetic and food additives. This review describes the recent advances made in the genetic and metabolic engineering of the terpenes pathway with a particular focus on systems biotechnology.     

Engineering microbial factories for synthesis of value-added products

Microorganisms have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. Advances in protein engineering, metabolic engineering, and synthetic biology enable redesigning microbial cellular networks and fine-tuning physiological capabilities, thus generating industrially viable strains for the production of natural and unnatural value-added compounds. In this review, we describe the recent progress on engineering microbial factories for synthesis of valued-added products including alkaloids, terpenoids, flavonoids, polyketides, non-ribosomal peptides, biofuels, and chemicals. Related topics on lignocellulose degradation, sugar utilization, and microbial tolerance improvement will also be discussed.     

Synthetic biology and metabolic engineering of actinomycetes for natural product discovery

Actinomycetes are one of the most valuable sources of natural products with industrial and medicinal importance. After more than half a century of exploitation, it has become increasingly challenging to find novel natural products with useful properties as the same known compounds are often repeatedly re-discovered when using traditional approaches. Modern genome mining approaches have led to the discovery of new biosynthetic gene clusters, thus indicating that actinomycetes still harbor a huge unexploited potential to produce novel natural products. In recent years, innovative synthetic biology and metabolic engineering tools have greatly accelerated the discovery of new natural products and the engineering of actinomycetes. In the first part of this review, we outline the successful application of metabolic engineering to optimize natural product production, focusing on the use of multi-omics data, genome-scale metabolic models, rational approaches to balance precursor pools, and the engineering of regulatory genes and regulatory elements. In the second part, we summarize the recent advances of synthetic biology for actinomycetal metabolic engineering including cluster assembly, cloning and expression, CRISPR/Cas9 technologies, and chassis strain development for natural product overproduction and discovery. Finally, we describe new advances in reprogramming biosynthetic pathways through polyketide synthase and non-ribosomal peptide synthetase engineering. These new developments are expected to revitalize discovery and development of new natural products with medicinal and other industrial applications.     

Recent advances in natural products exploitation in Streptomyces via synthetic biology

Natural products of microbial origin have proven to be the wellspring of clinically useful compounds for human therapeutics. Streptomyces species are predominant sources of bioactive compounds, most of which serve as potential drug candidates. While the exploitation of natural products has been severely reduced over the past two decades, the growing crisis of evolution and dissemination of drug resistant pathogens have again attracted great interest in this field. The emerging synthetic biology has been heralded as a new bioengineering platform to discover novel bioactive compounds and expand bioactive natural products diversity and production. Herein, we review recent advances in the natural products exploitation of Streptomyces with the applications of synthetic biology from three major aspects, including recently developed synthetic biology tools, natural products biosynthetic pathway engineering strategies as well as chassis host modifications.     

Rational design for over-production of desirable microbial metabolites by precision engineering

Microbes represent a valuable source of commercially significant natural products that have improved our quality of life. Precision engineering can be used to precisely identify and specifically modify genes responsible for production of natural products and improve this production or modify the genes creating products that would not otherwise be produced. There have been several success stories concerning the manipulation of regulatory genes, pathways, and genomes to increase the productivity of industrial microbes. This review will focus on the strategies and integrated approaches for precisely deciphering regulatory genes by various modern techniques. The applications of precision engineering in rational strain improvement also shed light on the biology of natural microbial systems.     

植物多酚的微生物合成

植物多酚属于苯丙烷衍生物,包括酚酸类、茋类、姜黄素类和黄酮类等。它们具有抗氧化、扩血管、抗血凝、抗炎、抗肿瘤、抗病毒等生理药理活性,在医药、食品、化妆品、化工等领域具有巨大的应用市场。微生物具有生长快、培养简单、可工业化等优点,成为异源合成天然产物的重要宿主。近年来,合成生物学的发展促进了植物天然产物的微生物合成,并取得了实质性进展。文中综述了植物多酚代谢途径在工程大肠杆菌、酿酒酵母等微生物中的构建、表达和产物合成现状,讨论了提高产量的前体工程、动态调控、共培养等优化策略,并就未来的多酚途径工程提出展望。     

Structure-driven protein engineering for production of valuable natural products

Proteins are the most frequently used biocatalysts, and their structures determine their functions. Modifying the functions of proteins on the basis of their structures lies at the heart of protein engineering, opening a new horizon for metabolic engineering by efficiently generating stable enzymes. Many attempts at classical metabolic engineering have focused on improving specific metabolic fluxes and producing more valuable natural products by increasing gene expression levels and enzyme concentrations. However, most naturally occurring enzymes show limitations, and such limitations have hindered practical applications. Here we review recent advances in protein engineering in synthetic biology, chemoenzymatic synthesis, and plant metabolic engineering and describe opportunities for designing and constructing novel enzymes or proteins with desirable properties to obtain more active natural products.     

Structure guided approaches toward exploiting and manipulating nonribosomal peptide and polyketide biosynthetic pathways

Nonribosomal peptide and polyketide natural products are structurally diverse small molecules synthesized on complex enzyme assemblies. The ability to rationally engineer secondary metabolic pathways is a promising approach to novel therapeutics. Atomic resolution structures of biosynthetic enzymes provide information on active site architecture and macromolecular assembly that can aid in the engineering of new compounds. This review surveys recent applications toward biosynthetic engineering of natural products guided by structural biology.