医薬品リード化合物の標的タンパク質に対する作用機序に関する研究

学位の種別: 論文博士審査委員会委員 : （主査）東京大学教授 大西 康夫, 東京大学教授 清水 謙多郎, 東京大学教授 吉田 稔, 東京大学教授 伏信 進矢, 東京大学講師 勝山 陽平University of Tokyo(東京大学

Engineered polyketide biosynthesis and biocatalysis in Escherichia coli

Polyketides are important bioactive natural products biosynthesized by bacteria, fungi, and plants. The enzymes that synthesize polyketides are collectively referred to as polyketide synthases (PKSs). Because many of the natural hosts that produce polyketides are difficult to culture or manipulate, establishing a universal heterologous host that is genetically tractable has become an important goal toward the engineered biosynthesis of polyketides and analogues. Here, we summarize the recent progresses in engineering Escherichia coli as a heterologous host for reconstituting PKSs of different types. Our increased understanding of PKS enzymology and structural biology, combined with new tools in protein engineering, metabolic engineering, and synthetic biology, has firmly established E. coli as a powerful host for producing polyketides

Advances in Pathway Engineering for Natural Product Biosynthesis

Biocatalysts provide an efficient, inexpensive and environmentally friendly alternative to traditional organic synthesis, especially for compounds with complex stereochemistries. The past decade has seen a significant rise in the use of biocatalysts for the synthesis of compounds in an industrial setting; however, the incorporation of single enzymatically catalysed steps into organic synthesis schemes can be problematic. The emerging field of synthetic biology has sparked interest in the development of whole-cell factories that can convert simple, common metabolites into complex, high-value molecules with a range of applications such as pharmaceuticals and biofuels. This Review summarises conventional methods and recent advances in metabolic engineering of pathways in microorganisms for the synthesis of natural products

Synthesis of Unnatural Flavonoids and Stilbenes by Exploiting the Plant Biosynthetic Pathway in Escherichia coli

SummaryFlavonoids and stilbenes have attracted much attention as potential targets for nutraceuticals, cosmetics, and pharmaceuticals. We have developed a system for producing “unnatural” flavonoids and stilbenes in Escherichia coli. The artificial biosynthetic pathway included three steps. These included a substrate synthesis step for CoA esters synthesis from carboxylic acids by 4-coumarate:CoA ligase, a polyketide synthesis step for conversion of the CoA esters into flavanones by chalcone synthase and chalcone isomerase, and into stilbenes by stilbene synthase, and a modification step for modification of the flavanones by flavone synthase, flavanone 3β-hydroxylase and flavonol synthase. Incubation of the recombinant E. coli with exogenously supplied carboxylic acids led to production of 87 polyketides, including 36 unnatural flavonoids and stilbenes. This system is promising for construction of a larger library by employing other polyketide synthases and modification enzymes