• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.157-160
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• 2003

ALA is an intermediate in the tetrapyrrole biosynthesis pathway and has extensive applications as a biodegradable herbicide and insecticide as well as medical applications including photodynamic therapy of cancers. For the development of mass production process of ALA it is necessary to on-line monitor some metabolites such as glycine, succinate, LA and ALA. In this study, medium compositions and fermentation conditions were investigated for enhancement of ALA production by recombinant E. coli. A 2-dimensional fluorescence sensor was employed to monitor the bioprocess of ALA production. The monitored data is analyzed using principal component analysis, a powerful tool for multivariate statistical analysis.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.87-90
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• 2003

ALA is an essential intermediate in the tetrapyrrole biosynthesis pathway and has applications as a biodegradable herbicide and insecticide as well as medical applications including photodynamic therapy of cancers. For the development of mass production process of ALA it is necessary to on-line monitor some metabolites such as glycine, succinate, LA and ALA. In this work, medium compositions, pH conditions, induction and addition of LA were investigated to increase the production of ALA by recombinant E. coli. A 2-dimensional fluorescence sensor was used to monitor the processe and the fluorescence spectra were correlated with on- and off-line data like ALAS, ALAD, cell mass etc.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.453-459
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• 2013

In phtosynthetic light harvesting complexes, the electronic transition energies of chlorophylls are influenced by the Coulombic interaction with nearby molecules. Variation of the interactions caused by structural inhomogeneity in biological environment results in a distribution of disordered electronic transition energies of chlorophylls. In order to provide a practical guide to predict qualitative tendency of such distribution, we model four porphyrin derivatives including chlorophyll a molecule interacting with an external positive charge and calculate their transition energies using the time dependent density functional method. It is found that ${\pi}-{\pi}^*$ transition energies of the molecules are generally blue-shifted by the charge because this stabilizes occupied molecular orbitals to a greater extent than unoccupied ones. Furthermore, new transitions in the visible region emerge as a result of the red-shift in energy of an unoccupied Mg orbital and it is suggested that light-induced electron transfer may occur from the tetrapyrrole ring to the central magnesium when the molecules are interacting with a positive charge.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.251-256
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• 2005

Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. To better understand the molecular mechanisms of cytokinin action, we identified cytokinin related proteins by a proteomic approach. Proteins extracted from control and trans-zeatin treated Arabidopsis seedlings were separated and analyzed by two dimensional gel analysis. Differentially expressed protein spots were identified with peptide mass fingerprinting based on matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and database searching, We obtained ten up-regulated and one down-regulated proteins upon t-zeatin treatment. The expression of the following proteins was induced; pollen allergen like protein, L-ascorbate peroxidase, tetrapyrrole methylase family protein, SGT1 protein homolog, disease resistance related protein, maternal embryogenesis control protein, paxneb related protein, gluthathione S-transferase and IAA amino acid hydrolase homolog.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.150-159
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• 1996

This study was conducted to investigate the inhibition of protox activity and the PPIX accumulation of the oxyfluorfen-tolerant and-susceptible rice cultivars with barnyardgrass, a typical susceptible weed in accordance by oxyfluorfen treatment. The susceptible rice cultivars and barnyardgrass showed more inhibition of protox activity due to the treatment of oxyfluorfen than the tolerant rice cultivars. Especially in the concentration at $10^{-6}$M treatment, protox activity of the susceptible rice cultivars and barnyardgrass were the completely inhibited but the tolerant rice cultivars kept 32~59% of activity compared to the control. As the treatment concentration increased, the content of PPIX accumulation increased and it increased untill four hours of light exposure but it tended to decrease these after. The content of PPIX accumulation by the treatment of oxyfluorfen was more pronounced in the light condition than in the dark. Under the light and dark conditions, the susceptible rice cultivars and barnyardgrass showed more PPIX accumulation than the tolerant rice cultivate. Especialiy the susceptible barnyardgrass had more than the rice. With the treatment of GC and DA, tetrapyrrole biosynthesis inhibitor, the herbicidal activity by oxyfluorfen was inhibited, and the susceptible rice cultivars and barnyardgrass tended to have less effective than the tolerant rice cultivars and the content of chlorophyll or PPS accumulation tended to be similar.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.337-345
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• 1996

This study was conducted to investigate the protox activity, the PPIX accumulation and the activity of antioxidative enzymes of the oxyfluorfen-tolerant and -susceptible rice cultivars by oxyfluorfen and oxytluorfen-similar herbicides treatment. When treated with acifluorfen, bifenox or oxadiazon, the oxyfluorfen-tolerant rice cultivars showed less decreased in fresh weight than the susceptible rice cultivars. The inhibition of protox activity was in the order of acifluorfen > oxyfluorfen > bifenox > oxadiazon, and the PPIX accumulation was in the sequence of oxadiazon > acifluorfen > oxyfluorfen > bifenox. The inhibition of protox activity and the PPIX accumulation by the herbicide was greater in the susceptible rice cultivars than in the tolerant rice cultivars. The effect inhibiting the decrease of chlorophyll content resulting from the treatment of GC, tetrapyrrole biosynthesis inhibitor, was in the order of oxyfluorfen > acifluorfen > bifenox > oxadiazon, and the tolerant rice cultivar had more than the susceptible rice cultivar. In the treatment of DPE and oxadiazon, the activities of MDAR, POX and GR was higher in the tolerant rice cultivar than in the susceptible rice cultivar, and in the case of POX isozyme the activities of main D and E bands increased in the tolerant rice cultivars at tested herbicides but they didn't in the susceptible rice cultivar.

• BMB Reports
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• v.43 no.5
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• pp.330-336
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• 2010

5-Aminolevulinate (ALA) is well-known as an essential biosynthetic precursor of all tetrapyrrole compounds, which has been suggested to improve plant salt tolerance by exogenous application. In this work, the gene encoding aminolevulinate synthase (ALA-S) in yeast (Saccharomyces cerevisiae Hem1) was introduced into the genome of Arabidopsis controlled by the Arabidopsis thaliana HemA1 gene promoter. All transgenic lines were able to transcribe the YHem1 gene, especially under light condition. The chimeric protein (YHem1-EGFP) was found co-localizing with the mitochondria in onion epidermal cells. The transgenic Arabidopsis plants could synthesize more endogenous ALA with higher levels of metabolites including chlorophyll and heme. When the $T_2$ homozygous seeds were cultured under NaCl stress, their germination and seedling growth were much better than the wild type. Therefore, introduction of ALA-S gene led to higher level of ALA metabolism with more salt tolerance in higher plants.

• Journal of the Korean Magnetic Resonance Society
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• v.3 no.1
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• pp.44-51
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• 1999

An enzyme derived conformational changes of cobalamine is thought to be important in the homolytic cleavage of Co-C bond which is the first step of catalytic Cl-cycle of coenzyme B12-dependent enzymes. Modern 2D-NMR and NMR-based distance geometric studies were carried out to determine the 3D structure of corrin ring. Homonuclear and heteronuclear correlation NMR experiments were performed for complete 1H-NMR signal assignments. Distances between numerous proton pairs were deduced based on the NOE cross peak intensities and subsequently used as input into the distance geometry program for the 3D structure determination. The detailed 3D structure from the present NMR-based analysis was compared with the result from X-ray crystallographic study, which revealed greater conformational changes occur in benzimidazole group and sugar ring than in macrocyclic corrin and tetrapyrrole. In addition, the distance geometry used in this study was found to be quite useful for NMR-based structure determination of medium-sized molecules that give poor NOE effects arising from their intermediate tumbling rate ($\omega$$\tau$c 1.0).

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.268-275
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• 2006

ALA (5-aminolevulinic acid) has been proposed as a tetrapyrrole-dependent photodynamic herbicide by the action of the protoporphyrinogen IX oxidase (Protox IX). A study was conducted to determine photodynamic herbicidal effect of ALA on seedling growth of rice (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli Beauv. var. oryzicola Ohwi) under dry and wet conditions. ALA effect on early plant growth of rice and barnyardgrass was greatly concentration dependant, suggesting that it promotes plant growth at very low concentration and inhibits at high concentration. No significant difference in herbicidal activity of biologically and synthetically produced ALAs on plant lengths of test plants was observed ALA exhibited significant photodynamic activity regardless of PSDIP and its duration. Significant shoot growth inhibition by ALA soaking treatment exhibited apparently, indicating that ALA absorbed through root system was translocated into shoot part of plants. ALA reduced plant heights of rice and barnyardgrass seedlings by 6% and 27%, respectively, showing more tolerant to ALA in rice under wet condition. Leaf thickness was reduced markedly by ALA with increasing of ALA concentration, due to mainly membrane destruction and severe loss of turgidity in mesophyll cells, although the epidermal was little affected. It was observed that photodynamic herbicidal activity of ALA applied by pre-and post-emergence application exhibited differently on plant species, and that the activity of ALA against susceptible plants was highly correlated with growing condition.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.36-43
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• 2014

Magnesium-protoporphyrin IX (Mg-PPn), which is formed through chelation of protoporphyrin IX (PPn) with Mg ion by Mg chelatase, is the first intermediate for the (bacterio)chlorophyll biosynthetic pathway. Interestingly, Mg-PPn provides peroxidase activity (approximately $4{\times}10^{-2}units/{\mu}M$) detoxifying $H_2O_2$ in the presence of electron donor(s). The peroxidase activity was not detected unless PPn was chelated with Mg ion. Mg-PPn was found freely diffusible through the membrane of Escherichia coli and Vibrio vulnificus, protecting the cells from $H_2O_2$. Furthermore, unlike photosensitizers such as tetracycline and PPn, Mg-PPn did not show any phototoxicity, but rather it protected cell from ultraviolet (UV)-A-induced stress. Thus, the exogenous Mg-PPn could be used as an antioxidant and a UV block to protect cells from $H_2O_2$ stress and UV-induced damage.