• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.158-158
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• 1998

The non-mevalonate pathway is a newly discovered isoprenoid biosynthetic pathway in some bacteria, cyanobacteria, algae and plants. Because isoprenoid metabolites (ubiquinone, menaquinone, undecaprenol) are essential for bacterial growth, this pathway may represent a novel target for antibacterial agents. Antibiotics with a unique mechanism of action are needed to combat the risk of antibiotic resistance that is a current worldwide problem. In order to study this pathway as viable target, it was necessary to verify use of the pathway in our model system, the bacterium Bacillus subtilis. Incubation experiments with [6,6-$^2$H$_2$]-D-glucose and [l-$^2$H$_3$]-deoxy-D-xylulose were conducted to provide labeled menaquinone-7 (MK -7), the most abundant isoprenoid in B. subtilis. $^2$H-NMR analysis of the MK-7 revealed labeling patterns that strongly support utilization of the non-mevalonate pathway. Another approach to study the pathway is by structure activity relationships of proposed inhibitors of the pathway. Fosmidomycin is a phosphonic acid with antibacterial activity known to inhibit isoprenoid biosynthesis in susceptible bacteria and may act by inhibiting the non-mevalonate pathway. Fosmidomycin and an N-methyl analog were synthesized and tested for antibacterial activity. Fosmidomycin was active against Escherichia coli and B. subtilis, while N-formyl-N-methyl-3-amino-propylphosphonic acid was inactive.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2012.05a
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• pp.20-20
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• 2012

Isoprenoids represent the most diverse group of metabolites, which are functionally and structurally identified in plant organism to date. Ginsenosides, glycosylated triterpenes, are considered to be the major pharmaceutically active ingredient of ginseng. Its backbones, categorized as protopanaxadiol (PPD), protopanaxatriol (PPT), and oleanane saponin, are synthesized via the isoprenoid pathway by cyclization of 2,3-oxidosqualene mediated with dammarenediol synthase or beta-amyrin synthase. The rate-limiting 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), which is the first committed step enzyme catalyzes the cytoplasmic mevalonate (MVA) pathway for isoprenoid biosynthesis. DXP reductoisomerese (DXR), yields 2-C-methyl-D-erythritol 4-phosphate (MEP), is partly involved in isoprenoid biosynthesis via plastid. Squalene synthase and squalene epoxidase are involved right before the cyclization step. The triterpene backbone then undergoes various modifications, such as oxidation, substitution, and glycosylation. Here we will discuss general biosynthesis pathway for the production of ginsenoside and its modification based on their subcellular biological functions.

• Molecules and Cells
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• v.22 no.3
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• pp.269-274
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• 2006

In order to characterize saikosaponin biosynthesis in Bupleurum falcatum, the expression of five isoprenoid pathway genes and their relationship to saikosaponin accumulation in the hairy roots were analyzed. The hairy roots exhibited a rapid accumulation of saikosaponins when incubated in a root culture medium (3XRCM). Homology-based RT-PCR was used to isolate core fragments of five genes, HMGR, IPPI, FPS, SS, and OSC, from the hairy roots. The deduced amino acid sequences exhibited amino acid identities of more than 85% to previously reported genes. Using the fragments as probes, the expression of these five genes in the hairy roots during incubation in 3XRCM medium was examined. Expression of all five genes in the hairy roots increased soon after incubation. In particular, the SS and OSC genes were coordinately induced at 8 days of incubation, and their expression persisted throughout the incubation period. A quantitative HPLC analysis showed that the saikosaponin content of the hairy root culture also began to increase at 8 days of culture. The correlation between SS transcript level and saikosaponin content in the hairy roots suggests that transcriptional regulation plays a regulatory role in saikosaponin biosynthesis.

• Journal of Life Science
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• v.18 no.12
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• pp.1764-1770
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• 2008

The goal of this study is to increase production of astaxanthin in recombinant Escherichia coli by engineered isoprenoid pathway. We have previously reported structural and functional analysis of the astaxanthin biosynthesis genes from a marine bacterium, Paracoccus haeundaensis. The carotenoid biosynthesis gene cluster involved in astaxanthin production contained six carotenogenic genes (crtW, crtZ, crtY, crtI, crtB, and crtE genes) and recombinant E. coli harboring six carotenogenic genes from P. haeundaensis produced 400 ${\mu}g$/g dry cell weight (DCW) of astaxanthin. In order to increase production of astaxanthin in recombinant E. coli, we have cloned 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (lytB), farnesyl diphosphate (FPP) synthase (ispA), and isopentenyl (IPP) diphossphate isomerase (idi) in the isoprenoid pathway from E. coli and coexpressed these genes in recombinant E. coli harboring the astaxanthin biosynthesis genes. This engineered E. coli strain containing both isoprenoid pathway gene and astaxanthin biosynthesis gene cluster produced 1,200 ${\mu}g$/g DCW of astaxanthin, resulting 3-fold increased production of astaxanthin.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.189-195
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• 2012

In plants, the fifth step of the plastidial 2-Cmethyl-D-erythritol 4-phosphate (MEP) pathway is catalyzed by 2-C-Methyl-D-erythritol 2,4-cyclodiphosphate synthase (MECP; EC: 4. 6. 1. 12), an enzyme proposed to play a key role in the regulation of isoprenoid biosynthesis. Here we report the isolation and functional characterization of a 823 bp Brassica rapa MECP (Brmecp) cDNA encoding a deduced polypeptide of 230 amino acid residues. Transcription levels of Brmecp were two-fold higher in petal compared to leaves. In addition, Brmecp expression in cabbage seedlings treated with ABA, $H_2O_2$ and drought was higher than control seedlings. These results were consistent with changes in chlorophyll contents in transgenic Arabidopsis. Thus, the Brmecp may contribute to the production of primary (chlorophylls and carotenoids) isoprenoid end-products in chloroplasts.

• Molecules and Cells
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• v.19 no.2
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• pp.294-299
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• 2005

A cDNA encoding farnesyl diphosphate synthase (FPS; EC2.5.1.1/EC2.5.1.10) was isolated from Centella asiacita (L.) Urban, using degenerate primers based on two highly conserved domains. A full-length cDNA clone was subsequently isolated by rapid amplification of cDNA ends (RACE) PCR. The sequence of the CaFPS (C. asiatica farnesyl diphosphate synthase) cDNA contains an open reading frame of 1029 nucleotides encoding 343 amino acids with a molecular mass of 39.6 kDa. The deduced CaFPS amino acid sequence exhibits 84, 79, and 72%, identity to the FPSs of Artemisia annua, Arabidopsis thaliana, and Oryza sativa, respectively. Southern blot analysis suggested that the C. asiatica genome contains only one FPS gene. An artificially expressed soluble form of the CaFPS was identified by SDS-PAGE. It had high specific activity and produced farnesyl diphosphate as the major isoprenoid.

• Korean Circulation Journal
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• v.48 no.11
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• pp.951-963
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• 2018

HMG-CoA reductase inhibitors, i.e. statins, are effective in reducing cardiovascular disease events but also in cardiac-related and overall mortality. Statins are in general well-tolerated, but currently the concerns are raised if statins may increase the risk of new-onset diabetes mellitus (NOD). In this review, the possible effects of statins on organs/tissues being involved in glucose metabolism, i.e. liver, pancreas, adipose tissue, and muscles, had been discussed. The net outcome seems to be inconsistent and often contradictory, which may be largely affected by in vitro experimental settings or/and in vivo animal conditions. The majority of studies point out statin-induced changes of regulations of isoprenoid metabolites and cellassociated cholesterol contents as predisposing factors related to the statin-induced NOD. On the other hand, it should be considered that dysfunctions of isoprenoid pathway and mitochondrial ATP production and the cholesterol homeostasis are already developed under (pre)diabetic and hypercholesterolemic conditions. In order to connect the basic findings with the clinical manifestation more clearly, further research efforts are needed.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.10a
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• pp.177-177
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• 2003

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.189-189
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.196-196
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• 2004