Earticle

초록

영어

Carotenoids are a structurally diverse group of natural pigmented chemicals of emerging importance as food supplements or colorants and in nutraceutical and pharmaceutical applications1). Carotenoids are structurally classified based on the number of backbone carbon molecules, usually C30, C40 or C50. Carotenoid biosynthesis occurs via a head to head condensation reaction of isoprenoid precursors followed by a desaturation reaction to increase the number of conjugated double bonds generating the distinctive carotenoid chromophore. Non-carotenogenic Escherichia coli cells can be transformed with heterologous carotenoid biosynthetic pathway genes of microbial or plant sources for the production of structurally diverse of carotenoids1). A new carotenoid desaturase homologue from S. aureus (CrtOx) was identified2). When expressed in engineered E. coli cells synthesizing linear C30 carotenoids3), novel polar carotenoid products were generated, identified as aldehyde and carboxylic acid C30 carotenoid derivatives. The major product in this engineered pathway is the fully desaturated C30 dialdehyde carotenoid 4,4’-diapolycopen-4,4’-dial. Very low carotenoid yields were observed when CrtOx was complemented with the C40 carotenoid lycopene pathway. But extension of an in vitro evolved pathway of the fully desaturated 2,4,2’,4’-tetradehydrolycopene produced the structurally novel fully desaturated C40 dialdehyde carotenoid 2,4,2’,4’-tetradehydrolycopendial. Directed evolution of CrtOx by error-prone PCR resulted in a number of variants with higher activity on C40 carotenoid substrates and improved product profiles. These findings may provide new biosynthetic routes to highly polar carotenoids with unique spectral properties desirable for a number of industrial and pharmaceutical applications. These results also demonstrate the utility of extending an in vitro evolved central metabolic pathway with catalytically promiscuous downstream enzymes in order to generate structurally novel compounds that are inaccessible without directed evolution4).

저자

• Pyung Cheon Lee [ Department of Molecular Science and Technology & Department of Biotechnology Ajou University ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국생물공학회 학술대회

• 간기

  반년간

• 수록기간

  1985~2013

• 십진분류

  KDC 476 DDC 576