• KSBB Journal
• /
• v.29 no.4
• /
• pp.244-249
• /
• 2014

Biosynthesis pathway of medium-chain-length (MCL) polyhydroxyalkanoates (PHA) from fatty acid ${\beta}$-oxidation pathway was constructed in recombinant Escherichia coli by introducing the Pseudomonas sp. 61-3 PHA synthase gene (phaC2) and the maoC genes from Pseudomonas putida, Sinorhizobium meliloti, and Ralstonia eutropha. The metabolic link between fatty acid ${\beta}$-oxidation pathway and PHA biosynthesis pathway was constructed by MaoC, which is homologous to P. aeruginosa (R)-specific enoyl-CoA hydratase (PhaJ1). When the E. coli W3110 strains expressing the phaC2 gene and one of the maoC genes from P. putida, Sinorhizobium meliloti, and Ralstonia eutropha were cultured in LB medium containing 2 g/L of sodium decanoate as a carbon source, MCL-PHA that mainly consists of 3-hydroxyhexanoate (3HHx), 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD), was produced. The monomer composition of PHA and PHA contents varied depending on MaoC employed for the production of PHA. The highest PHA content of 18.7 wt% was achieved in recombinant E. coli W3110 expressing the phaC2 gene and the P. putida maoC gene. These results suggest that MCL-PHA biosynthesis pathway can be constructed in recombinant E. coli strains from the b-oxidation pathway by employing MaoC able to supply (R)-3-hydroxyacyl-CoA, the substrate of PHA synthase.

• Journal of Plant Biotechnology
• /
• v.5 no.3
• /
• pp.149-155
• /
• 2003

Metabolic engineering for production of isoflavones in nonlegume plants could distribute the health benefits of these phytoestrogens in more widely-consumed grains. Series of investigation to check the ability of the heterologous isoflavone synthase enzyme to interact with the endogenous phenylpropanoid pathway have been conducted. Overall, results provide possibility of production of isoflavonoids in several plant tissue systems including soybean and nonlegumes. In tissue that undergoes naturally enhanced synthesis of anthocyanins, genistein production was enhanced. In a monocot cell system, introduced expression of a transcription factor regulating genes of the anthocyanin pathway was effective in conferring the ability to produce genistein in the presence of the isoflavone synthase gene. However, in this case the intermediate accumulated to high levels indicating an inefficiency in its conversion. Introduction of a third gene, chalcone reductase, provided the ability to synthesize an additional substrate of isoflavone synthase resulting in production of the isoflavone daidzein. These research efforts provide insight into requirements for metabolic engineering for isoflavone production in nonlegume dicot and monocot tissues.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.1
• /
• pp.63-67
• /
• 1994

A microorganism showing degradative activity towards benzene, toluene and ${\rho}-xylene$ (BTX) was isolated from an activated sewage sludge and was tentatively identified as Pseudomonas fluorescence BE103. This strain was found to utilize benzene and toluene as growth substrates, but to degrade ${\rho}-xylene$ in the obligate presence of a growth substrate. The metabolic product resulted from the cometabolism of ${\rho}-xylene$ was identified as 3, 6-dimethylpyrocatechol by LC/MS analysis, and the metabolic pathway was analyzed to be similar to the tod pathway. From the kinetic studies done regarding BTX biodegradation using Pseudomonas fluorescence BE103, it was revealed that the cometabolism of ${\rho}-xylene$ is significantly affected by the ratio of growth substrate concentration to biomass concentration, and that the cometabolism of ${\rho}-xylene$ initiates only when this ratio was about 0.03.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04b
• /
• pp.295-297
• /
• 2004

유전자의 생물학적 기능을 밝히고 세포 내 상호작용을 이해하는 것은 post-genome era의 가장 중요한 작업 중 하나이다. 이러한 세포 내 상호작용은 복잡한 생화학적 네트워크를 형성하게 되며 그 중 Metabolic pathway(대사 경로)는 생물 시스템을 이해하는데 가장 중요한 부분을 차지하게 된다. 대사 경로를 분석하기 위하여 분자의 기능 및 생화학적 프로세스에 대한 정보를 데이터베이스에 저장.관리해야하고, 사용자의 다양한 질의에 대하여 관련정보를 검색하여 GUI환경에서 제공해야 한다. 이 논문은 대사 경로 정보를 객체 데이타베이스 형태로 모델링하여 구축하고, 사용자가 관심있는 정보를 SBML형태로 제공하는 대사경로 데이타베이스의 설계 및 구현에 관해 다룬다.

• Archives of Pharmacal Research
• /
• v.20 no.5
• /
• pp.420-424
• /
• 1997

By human intestinal bacteria, saikosaponin c was transformed to four metabolites, prosaikogenin E1 (E1) prosaikogenin E2 (E2), prosaikogenin E3 (E3) and saikogenin E. Metabolic time course of saikosaponin c was as follows; in early time, saikosaponin c was converted to E1 and E2, and then these were transformed to saikogenin E via E3. Also, this metabolic pathway was similar to the metabolism of saikosaponin c by rat intestinal bacteria. Bacteroides JY-6 and Bacteroides YK-4, the bacteria isolated from human intestinal bacteria, could transform saikosaponin c to E via E1 (or E2) and E3. However, these bacteria were not able to directly transform El and E2 to saikogenin E. Naringin was mainly transformed to naringenin by human intestinal bacteria. The minor metabolic pathway transformed naringin to naringenin via prunin. By JY-6 or YK-4, naringin was metabolized to naringenin only via prunin.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.1
• /
• pp.1-13
• /
• 2016

The evidence for the existence of a common pathway for health issues in men is presented in this review. Several epidemiological studies have shown that conditions like cardiovascular diseases (CVD), metabolic syndrome, diabetes, lower urinary tract symptom (LUTS), erectile dysfunction (ED), prostate cancer, hypogonadism, depression and suicide can be associated as risk factors for each other. Thus, the risk of CVD is significantly increased in men with metabolic syndrome, ED, hypogonadism, prostate cancer and/or LUTS. In addition, the above mentioned conditions are more prevalent in atherosclerotic patients. In addition, growing evidence indicates that low androgen levels can cause metabolic syndrome. In addition, obesity, dyslipidaemia and diabetes can further reduce androgen levels potentiating their adverse effect. Low testosterone levels are also associated with a higher incidence of aggressive prostate cancer on biopsy and on definitive pathology, and lower probability of abiraterone response in the metastatic setting. Several recent studies point towards diffuse endothelial dysfunction and dysregulated pro-inflammatory state as the biological link between all these disorders. Our current hypothesis is that oxidative stress caused by these dysfunctions explains the pathogenesis of each of these conditions.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.5 no.4
• /
• pp.219-226
• /
• 2000

The application of recombinant DNA technology to restructure metabolic net-work can change metabolite and protein products by altering the biosynthetic pathways in an organism. Although some success has been achieved, a more detailed and thorough investigation of this approach is certainly warranted since it is clear that such methods hold great potential based on the encouraging results obtained so far. In last decade, there have been tremendous advances in the field of glycobiology and the stage has been set for the biotechnological production of glycoproteins for therapeutic use. Today glycoproteins are one of the most important groups of pharmaceutical products. In this study the attempt was made to focus on identifying technologies that may have general application for modifying glycosylation pathway of the yeast cells in order to produce glycoproteins of therapeutic use. The carbohydrates of therapeutic recombinant glycoproteins play very important roles in determining their pharmacokinetic properties. A number of biological interactions and biological functions mediated by glycans are also being targeted for therapeutic manipulation in vivo. For a commercially viable production of therapeutic glycoproteins a metabolic engineering of a host cell is yet to be established.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.7
• /
• pp.973-979
• /
• 2023

Lycopene is a carotenoid widely used as a food and feed supplement due to its antioxidant, anti-inflammatory, and anti-cancer functions. Various metabolic engineering strategies have been implemented for high lycopene production in Escherichia coli, and for this purpose it was essential to select and develop an E. coli strain with the highest potency. In this study, we evaluated 16 E. coli strains to determine the best lycopene production host by introducing a lycopene biosynthetic pathway (crtE, crtB, and crtI genes cloned from Deinococcus wulumuqiensis R12 and dxs, dxr, ispA, and idi genes cloned from E. coli). The 16 lycopene strain titers diverged from 0 to 0.141 g/l, with MG1655 demonstrating the highest titer (0.141 g/l), while the SURE and W strains expressed the lowest (0 g/l) in an LB medium. When a 2 × YTg medium replaced the MG1655 culture medium, the titer further escalated to 1.595 g/l. These results substantiate that strain selection is vital in metabolic engineering, and further, that MG1655 is a potent host for producing lycopene and other carotenoids with the same lycopene biosynthetic pathway.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.3
• /
• pp.272-287
• /
• 2019

The mechanistic target of rapamycin (mTOR) pathway coordinates the metabolic activity of eukaryotic cells through environmental signals, including nutrients, energy, growth factors, and oxygen. In the nervous system, the mTOR pathway regulates fundamental biological processes associated with neural development and neurodegeneration. Intriguingly, genes that constitute the mTOR pathway have been found to be germline and somatic mutation from patients with various epileptic disorders. Hyperactivation of the mTOR pathway due to said mutations has garnered increasing attention as culprits of these conditions : somatic mutations, in particular, in epileptic foci have recently been identified as a major genetic cause of intractable focal epilepsy, such as focal cortical dysplasia. Meanwhile, epilepsy models with aberrant activation of the mTOR pathway have helped elucidate the role of the mTOR pathway in epileptogenesis, and evidence from epilepsy models of human mutations recapitulating the features of epileptic patients has indicated that mTOR inhibitors may be of use in treating epilepsy associated with mutations in mTOR pathway genes. Here, we review recent advances in the molecular and genetic understanding of mTOR signaling in epileptic disorders. In particular, we focus on the development of and limitations to therapies targeting the mTOR pathway to treat epileptic seizures. We also discuss future perspectives on mTOR inhibition therapies and special diagnostic methods for intractable epilepsies caused by brain somatic mutations.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.16
• /
• pp.7031-7038
• /
• 2015

Background: Arginine may play important roles in tumor progression by providing ornithine for polyamine biosynthesis, required for cell growth. The aim of this work was to determine the expression of arginine metabolic pathway enzymes in head and neck squamous cell carcinoma (HNSCC) in northeast India. Materials and Methods: The expressions of arginase isoforms (ARG1 and ARG2), ornithine aminotransferase (OAT) and ornithine decarboxylase (ODC) were examined in fifty paired HNSCC and adjacent non-tumor tissues by immunohistochemistry. Immunocytochemistry, semiquantitative reverse transcription sq-PCR and quantitative real-time qPCR were used to assess protein and mRNA expressions in peripheral blood of fifty HNSCC patients and hundred controls. Results: ARG1 and ODC protein and mRNA were strongly expressed in peripheral blood from HNSCC patients. No ARG2 expression was observed. In vivo, expression of ARG1, ARG2 and ODC was significantly higher in tumor than in non-tumor tissues. Most tumors expressed low levels of OAT, with no difference in tissues or blood, compared to controls. The absolute extent of maximal ARG1 upregulation with qPCR showed 6.23 fold increase in HNSCC. Conclusions: These findings strongly suggest that in HNSCCs, the ARG1 pathway is stimulated leading to the formation of polyamines as indicated by higher ODC expression, which promote tumor growth.