• Korean Journal of Microbiology
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• v.39 no.4
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• pp.223-229
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• 2003

The purpose of this work was to perform the characterization of NAD(P)H-nitroreductase isolated from Stenotrophomonas sp. OK-5 capable of degrading 2,4,6-trinitrotoluene (TNT). Initially, NADP(H)-nitroreductase by a series of purification processes including ammonium sulfate precipitation, DEAE-sepharose, andQ-sepharose was prepared. From samples harvested from fraction collector, three different fractions (I, II & III)having the enzyme activity of NAD(P)H-itroreductase were detected. Specific activities of three fractions I, II,and III of NAD(P)H-nitroreductase were determined to approximately 5.06 unit/mg, 4.95 unit/mg and 4.86 unit/mg, and concentrated to 10.5, 9.8, and 8.9-fold compared to crude extract, respectively. Among these three fractions,the fraction I of NAD(P)H-nitroreductase demonstrated the highest specific activity in this experiment. Several factors affecting on the enzyme activity of NAD(P)H-nitroreductase (fractions I, II & III) were investigated.The optimum temperature of all NAD(P)H-nitroreductase (fractions I, II & III) was 30oC, and the optimal pH was approximately 7.5. Metal ions such as Ag+, Cu2+, Hg2+ inhibited approximately 80% enzyme activity of all NAD(P)H-nitroreductase, and the enzyme activities were decreased about 30-40% inhibition in the presence of Mn2+ or Ca2+. However, Fe3+ showed stimulatory effect on the enzyme activity. The molecular weights of NAD(P)H-nitroreductase (fractions I, II & III) were measured about 27 kDa on the SDS-PAGE.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.3
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• pp.238-246
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• 2012

Once oil is spilled into marine environment, it experiences various weathering processes among which evaporation is the most dominant process in the initial stage of weathering. This study aimed to elucidate the effects of evaporation on the physicochemical properties of spilled oil using standardized laboratory experiments. Laboratory evaporation process was successfully reproduced using controlled rotary evaporation method. In case of Iranian Heavy crude (IHC), evaporation rate after 48 hours was $29.3{\pm}0.4%$ (n=40, p<0.001). Evaporation was simulated using ADIOS2 weathering model and the result was in agreement with laboratory experiment. Chemical composition changes of petroleum hydrocarbons including alkanes, polycyclic aromatic hydrocarbons (PAHs) and biomarkers by evaporation rate were also analyzed. As oil evaporated, low molecular weight alkanes and PAHs decreased, while biomakers showed conservative characteristics. Among biomarkers, $17{\alpha}(H)$, $21{\beta}(H)$-hopane was used for calculation of weathering rates, which matched with evaporative mass losses. Weathering rate calculation using hopane showed that stranded oils of weathering stage I (28.9%) and mesocosm oil weathering experiment till 5 days (26.5%) were mainly affected by evaporation process.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.230-234
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• 2007

Oxygen is required for many important aerobic cellular reactions, it may undergo electrontransfer reactions, which generate highly reactive membrane-toxic intermediates (reactive oxygen species, ROS), such as hydrogen peroxide, singlet oxygen, superoxide radical, hydroxyl radical, hydroperoxyl radical, hydroxy ion. Various mechanisms are available to protect cells against damage caused by oxidative free radicals, including scavenging enzyme systems such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). This antioxidant defense system is a very complex and finely tuned system consisting of enzymes capable of detoxifying oxygen radicals as well as low molecular weight antioxidants. In addition, repair and turnover processes help to minimize subcellular damage resulting from free radical attack. $H_2O_2$,one of the major ROS, is produced at a high rate as a product of normal aerobic metabolism. The primary cellular enzymatic defense systems against $H_2O_2$ are the glutathione redox cycle and catalase. From Northern blot analysis of total RNAs from cultured cell with $H_2O_2$ treatment, various results were obtained. Expression of Cu/Zn SOD decreased when cell passage increased, but the level of the Cu/Zn SOD was scarcely expressed in 35 passage.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.912-919
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• 2017

Objective: Identification of the candidate genes that play key roles in phenotypic variations can provide new information about evolution and positive selection. Interleukin (IL)-32 is involved in many biological processes, however, its role for the immune response against various diseases in mammals is poorly understood. Therefore, the current investigation was performed for the better understanding of the molecular evolution and the positive selection of single nucleotide polymorphisms in IL-32 gene. Methods: By using fixation index ($F_{ST}$) based method, IL-32 (9375) gene was found to be outlier and under significant positive selection with the provisional combined allocation of mean heterozygosity and $F_{ST}$. Using nucleotide sequences of 11 mammalian species from National Center for Biotechnology Information database, the evolutionary selection of IL-32 gene was determined using Maximum likelihood model method, through four models (M1a, M2a, M7, and M8) in Codeml program of phylogenetic analysis by maximum liklihood. Results: IL-32 is detected under positive selection using the $F_{ST}$ simulations method. The phylogenetic tree revealed that goat IL-32 was in close resemblance with sheep IL-32. The coding nucleotide sequences were compared among 11 species and it was found that the goat IL-32 gene shared identity with sheep (96.54%), bison (91.97%), camel (58.39%), cat (56.59%), buffalo (56.50%), human (56.13%), dog (50.97%), horse (54.04%), and rabbit (53.41%) respectively. Conclusion: This study provides evidence for IL-32 gene as under significant positive selection in goat.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.920-929
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• 2017

Objective: The bursa of Fabricius (BF) is a central humoral immune organ belonging specifically to avians. Recent studies had suggested that miRNAs were active regulators involved in the immune processes. This study was to investigate the possible differences of the BF at miRNA level between two genetically disparate duck breeds. Methods: Using Illumina next-generation sequencing, the miRNAs libraries of ducks were established. Results: The results showed that there were 66 differentially expressed miRNAs and 28 novel miRNAs in bursa. A set of abundant miRNAs (i.e., let-7, miR-146a-5p, miR-21-5p, miR-17~92) which are involved in immunity and disease were detected and the predicted target genes of the novel miRNAs were associated with duck high anti-adversity ability. By gene ontology analysis and enriching KEGG pathway, the targets of differential expressed miRNAs were mainly involved in immunity and disease, supporting that there were differences in the BF immune functions between the two duck breeds. In addition, the metabolic pathway had the maximum enriched target genes and some enriched pathways that were related to cell cycle, protein synthesis, cell proliferation and apoptosis. It indicted that the difference of metabolism may be one of the reasons leading the immune difference between the BF of two duck breeds. Conclusion: This data lists the main differences in the BF at miRNAs level between two genetically disparate duck breeds and lays a foundation to carry out molecular assisted breeding of poultry in the future.

• Journal of Life Science
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• v.24 no.3
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• pp.323-328
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• 2014

MicroRNAs comprise a family of small noncoding RNAs that modulate physiological processes, including adipogenesis. MicroRNA-17 (miR-17) promotes adipocyte differentiation and enhances lipid accumulation. The transcriptional regulation of miR-17 during adipogenesis remains unknown. In this study, we investigated whether miR-17 is a target of peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$), which is a key regulator of adipogenesis. The levels of miR-17 and the expression of $PPAR{\gamma}$ increased after the induction of adipocyte differentiation. Three putative peroxisome proliferator response elements (PPREs) were identified in the miR-17 promoter region. Using chromatin immunoprecipitation and luciferase reporter assays, we observed the interaction of $PPAR{\gamma}$ with the miR-17 promoter. Mutagenesis experiments showed that the -677/-655 region of the miR-17 promoter could function as a PPRE site. These results suggest that $PPAR{\gamma}$ is essential for transcriptional activation of the miR-17 gene, thereby contributing to understanding the molecular mechanism of adipogenesis in adipocytes.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.665-670
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• 2016

The objectives of this study were conducted to characterize pepsin-soluble collagen (PSC) extracted from bones (PSC-B), skins (PSC-S), and tendons (PSC-T) of duck feet and to determine their thermal and structural properties, for better practical application of each part of duck feet as a novel source for collagen. PSC was extracted from each part of duck feet by using 0.5 M acetic acid containing 5% (w/w) pepsin. Electrophoretic patterns showed that the ratio between α₁ and α₂ chains, which are subunit polypeptides forming collagen triple helix, was approximately 1:1 in all PSCs of duck feet. PSC-B had slightly higher molecular weights for α₁ and α₂ chains than PSC-S and PSC-T. From the results of differential scanning calorimetry (DSC), higher onset (beginning point of melting) and peak temperatures (maximum point of curve) were found at PSC-B compared to PSC-S and PSC-T (p<0.05). Fourier transform infrared spectroscopy (FT-IR) presented that PSC-S and PSC-T had similar intermolecular structures and chemical bonds, whereas PSC-B exhibited slight difference in amide A region. Irregular dense sheet-like films linked by random-coiled filaments were observed similarly. Our findings indicate that PSCs of duck feet might be characterized similarly as a mixture of collagen type I and II and suggest that duck feet could be used for collagen extraction without deboning and/or separation processes.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.65-72
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• 1983

The composition of four rice protein groups is greatly affected by the extraction conditions. The extraction amounts of albumins and glubulines primarily depended on the temperature rather than the method of extraction. The total amount of glutelins, the major components of rice storage proteins, could be extracted by a successive extraction processes, extraction with 0.5% SDS-0.1M borate buffer(pH 8.3) followed by extraction with 0.5% SDS-0.6% ${\beta}-mercaptoethanol-0.1M$ borate buffer(pH 8.3). The extracted amounts of glutelin with these solvents were 54.1 and 45% respectively. The further purification of SDS soluble glutelins was achieved by Sephadex G-150 gel column chromatography. The molecular weight of the components in four protein groups has been estimated by SDS-polyacrylamide gel electrophoresis with or without ${\beta}-mercaptoethanol.$ The comparison of albumins and globulins by starch gel electrophoresis at pH 3.1 permitted us to identify seven rice varieties. However, at pH 8.95, the specific bands for Japonica type rice varieties were observed.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.149-156
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• 2011

Golgi SNAP receptor complex 1 (GS28) has been implicated in vesicular transport between intra-Golgi networks and between endoplasmic reticulum (ER) and Golgi. Additional role(s) of GS28 within cells have not been well characterized. We observed decreased expression of GS28 in rat ischemic hippocampus. In this study, we examined the role of GS28 and its molecular mechanisms in neuronal (SK-N-SH) cell death induced by hydrogen peroxide ($H_2O_2$). GS28 siRNA-transfected cells treated with $H_2O_2$ showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, which corresponded to an increase of intracellular reactive oxygen species (ROS) in the cells. Pretreatment of GS28 siRNA-transfected cells with p38 chemical inhibitor significantly inhibited cytotoxicity; we also observed that p38 was activated in the cells by immunoblot analysis. We confirmed the role of p38 MAPK in cotransfected cells with GS28 siRNA and p38 siRNA in the cell viability assay, flow cytometry, and immunoblot. Involvement of apoptotic or autophagic processes in the cells was not shown in the cell viability, flow cytometry, and immunoblot analyses. However, pretreatment of the cells with necrostatin-1 completely inhibited $H_2O_2$-induced cytotoxicity, ROS generation, and p38 activation, indicating that the cell death is necroptotic. Collectively these data imply that $H_2O_2$ induces necroptotic cell death in the GS28 siRNA-transfected cells and that the necroptotic signals are mediated by sequential activations in RIP1/p38/ROS. Taken together, these results indicate that GS28 has a protective role in $H_2O_2$-induced necroptosis via inhibition of p38 MAPK in GSH-depleted neuronal cells.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.349-361
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• 2010

In this review, the current knowledge of the carbon metabolism and global carbon regulation in Corynebacterium glutamicum are summarized. C. gluamicum has phosphotransferase system (PTS) for the utilization of sucrose, glucose, and fructose. C. glutamicum does not show any preference for glucose when various sugars or organic acids are present with glucose, and thus cometabolizes glucose with other sugars or organic acids. The molecular mechanism of global carbon regulation such as carbon catabolite repression (CCR) in C. glutamicum is quite different to that in Gram-negative or low-GC Gram-positive bacteria. GlxR (glyoxylate bypass regulator) in C. glutamicum is the cyclic AMP receptor protein (CRP) homologue of E. coli. GlxR has been reported to regulate genes involved in not only glyoxylate bypass, but also central carbon metabolism and CCR including glycolysis, gluconeogenesis, and tricarboxylic acid (TCA) cycle. Therefore, GlxR has been suggested as a global transcriptional regulator for the regulation of diverse physiological processes as well as carbon metabolism. Adenylate cyclase of C. glutamicum is a membrane protein belonging to class III adenylate cyclases, thus it could possibly be a sensor for some external signal, thereby modulating cAMP level in response to environmental stimuli. In addition to GlxR, three additional transcriptional regulators like RamB, RamA, and SugR are also involved in regulating the expression of many genes of carbon metabolism. Finally, recent approaches for constructing new pathways for the utilization of new carbon sources, and strategies for enhancing amino acid production through genetic modification of carbon metabolism or regulatory network are described.