• Journal of Microbiology
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• v.44 no.5
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• pp.492-501
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• 2006

In this study, we attempted to characterize the physiological response to oxidative stress by heat shock in Saccharomyces cerevisiae KNU5377 (KNU5377) that ferments at a temperature of $40^{\circ}C$. The KNU5377 strain evidenced a very similar growth rate at $40^{\circ}C$ as was recorded under normal conditions. Unlike the laboratory strains of S. cerevisiae, the cell viability of KNU5377 was affected slightly under 2 hours of heat stress conditions at $43^{\circ}C$. KNU5377 evidenced a time-dependent increase in hydroperoxide levels, carbonyl contents, and malondialdehyde (MDA), which increased in the expression of a variety of cell rescue proteins containing Hsp104p, Ssap, Hsp30p, Sod1p, catalase, glutathione reductase, G6PDH, thioredoxin, thioredoxin peroxidase (Tsa1p), Adhp, Aldp, trehalose and glycogen at high temperature. Pma1/2p, Hsp90p and $H^+$-ATPase expression levels were reduced as the result of exposure to heat shock. With regard to cellular fatty acid composition, levels of unsaturated fatty acids (USFAs) were increased significantly at high temperatures ($43^{\circ}C$), and this was particularly true of oleic acid (C18:1). The results of this study indicated that oxidative stress as the result of heat shock may induce a more profound stimulation of trehalose, antioxidant enzymes, and heat shock proteins, as well as an increase in the USFAs ratios. This might contribute to cellular protective functions for the maintenance of cellular homeostasis, and may also contribute to membrane fluidity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48
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• pp.13-23
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• 2003

The trace mineral, selenium (Se), is an essential nutrient of fundamental importance to human health. It is also very toxic and can cause Se poisoning (selenosis) in human and animals when its intake exceeds a suitable amount. Se functions within mammalian systems primarily in the form of solenoprotein. About 35 selenoproteins have been identified, though many have not yet been fully elucidated. Selenoproteins contain Se as selenocyseine (Sec) and perform variety of structural and enzymic roles; the enzymic roles are best-known as the antioxidants for hydrogen peroxides and lipid peroxides, and the catalysts for production of activity thyroid hormone. Glutathione peroxidases ($\textrm{GP}_X$) among the selenoproteins prevent the generation of free radicals and decrease the risk of oxidative damage to tissues, as does thioredoxin reductase (TR). TR also provides reducing power for several biochemical processes. Selenoproteins P and W are involved with oxidant defense in plasma and muscle, respectively, A selenoprotein is also required for sperm motility and may reduce the risk of miscarriage. Some epidemiological studies have revealed an inverse correlation between Se status and cardiovascular disease, and there is considerable evidence 1mm population com-parison data and animal studies that Se is anticarcinogenic. It is also suggested that Se should be needed for the proper functioning of the immune system, and appear to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. As research continues, the role of selenium in the etiology of chronic diseases like appropriate medical nutrition therapy can be delivered and its effectiveness assessed. Se status in individuals is affected by diet and the availability of the Se. The Se content of plants is affected by the content and availability of the element in the soil in which they are grown, and so greatly varies from country to country, while the Se composition of meat reflects the feeding patterns of livestock. This paper provides an overview on Se as an essential trace mineral for human.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.553-559
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• 1998

cDNA of human thrombopoietin (hTPO) amplified by polymerase chain reaction from a cDNA library of human fetal liver was cloned. EPO-like domains ($hTPO_{153} \;or\; hTPO_{l63})\; of\; hTPO(hTPO_{332}$) were expressed in Escherichin coli using several kinds of expression systems, such as ompA secretion, thioredoxin fusion, and the $P_L$ and T7 expression systems. To obtain $hTPO_{153}$ in soluble form, $hTPO_{153}$ cDNA was fused in-frame behind the gene encoding ompA signal sequence and thioredoxin protein. When fused with either of the genes, $hTPO_{153}$ was not expressed to the detectable level. However, a high level expression of the EPO-like domain of hTPO was obtained using the PL and T7 expression system. $hTPO_{153} \;or\; hTPO_{l63} cDNA were subcloned into the pLex and pET-28a(＋) vectors under the control of the inducible$ P_L\;T_7$ promoter, respectively. Proteins expressed using pl.ex vector and pET-28a(＋) detected in insoluble forms with an expression level of about 14% and 9% of total cellular proteins, respectively, and the level of expression was rapidly diminished in 2 h after the maximum level of expression was reached.

• Proceedings of the Botanical Society of Korea Conference
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• 1999.07a
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• pp.57-62
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• 1999

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

• Proceedings of the Botanical Society of Korea Conference
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• 1985.08b
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• pp.7-18
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• 1985

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.2.1-2.14
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• 2023

Background: Hypothermia is a crucial environmental factor that elevates the risk of cardiovascular disease, but the underlying effect is unclear. Objectives: This study examined the role of cold stress (CS) in cardiac injury and its underlying mechanisms. Methods: In this study, a chronic CS-induced myocardial injury model was used; mice were subjected to chronic CS (4℃) for three hours per day for three weeks. Results: CS could result in myocardial injury by inducing the levels of heat shock proteins 70 (HSP70), enhancing the generation of creatine phosphokinase-isoenzyme (CKMB) and malondialdehyde (MDA), increasing the contents of tumor necrosis factor-α (TNF-α), high mobility group box 1 (HMGB1) interleukin1b (IL-1β), IL-18, IL-6, and triggering the depletion of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Multiple signaling pathways were activated by cold exposure, including pyroptosis-associated NOD-like receptor 3 (NLRP3)-regulated caspase-1-dependent/Gasdermin D (GSDMD), inflammation-related toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK), as well as oxidative stressinvolved thioredoxin-1/thioredoxin-interacting protein (Txnip) signaling pathways, which play a pivotal role in myocardial injury resulting from hypothermia. Conclusions: These findings provide new insights into the increased risk of cardiovascular disease at extremely low temperatures.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.451-459
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• 1999

Background : In sepsis, excessive generation of reactive oxygen species plays key roles in the pathogenesis of acute lung injury. The serum antioxidants such as catalase and MnSOD are elevated in sepsis and considered as predictors of acute respiratory distress syndrome(ARDS) and prognostic factors of sepsis. Peroxiredoxin(Prx) has recently been known as an unique and major intracellular antioxidant. In this study, we evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells(RAW 267.7) after treatment of oxidative stress and endotoxin and measured the amount of Prx I, Prx II and thioredoxin(Trx) in peritoneal and bronchoalveolar lavage fluid of septic animal model. Methods : Using immunoblot analysis with specific antibodies against Prx I, Prx II and Trx, we evaluated the distribution of Prx I and Prx II in human neutrophil, alveolar macrophage and red blood cell. We evaluated the expression of Prx I and Prx II in mouse monocyte-macrophage cells after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide(LPS) and measured the amount of Prx I, Prx II and Trx in peritoneal lavage fluid of intraperitoneal septic animals(septic animal model induced with intraperitoneal 6 mg/Kg LPS injection) and those in bronchoalveolar lavage fluid of intraperitoneal septic animals and intravenous septic animals(septic animal model induced with intravenous 5 mg/Kg LPS injection) and compared with the severity of lung inflammation. Results : The distribution of Prx I and Prx II were so different among human neutrophil, alveolar macrophage and red blood cell. The expression of Prx I in mouse monocyte-macrophage cells was increased after treatment of $5\;{\mu}M$ menadione and $1\;{\mu}g/ml$ lipopolysaccharide but that of Prx II was not increased. The amount of Prx I, Prx II and Trx were increased in peritoneal lavage fluid of intraperitoneal septic animals but were not increased in bronchoalveolar lavage fluid of intraperitoneal and intravenous septic animals regardless of the severity of lung inflammation. Conclusion : As intracellular antioxidant, the expression of Prx I is increased in mouse monocyte-macrophage cells after treatment of oxidative stress and endotoxin. The amount of Prx I, Prx II and Trx are increased in local inflammatory site but not increased in injured lung of septic animal model.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2004.05a
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• pp.152-152
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• 2004

• Journal of Life Science
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• v.3 no.4
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• pp.194-208
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• 1993

DNA 복제시 중추적 단백질은 DNA 합성을 수행하는 DNA polymerase이다. 따라서 DNA polymerase의 구조 및 기능에 대한 연구는 DNA polymerase의 중합반응에 대한 기작을 비롯하여 교정 및 수선기능에 대한 정보를 얻게 함으로써 복잡한 DNA 복제 기적을 이해하는 첩경이 된다. Bacteriophage T7의 Gene 5 단백질은 T7 DNA polymerase로 Richardson group에 의해 처음으로 발견되었으며, E. coli의 12 KDa thioredoxin과 tight complex를 형성한다. T7 DNA polymerase의 클로닝은 분자생물학의 새로운 장을 열어준 중요한 의미를 지닌다 . 본 연구에서는 T7 DNA polymerase의 구조적, 기능적 특성을 파악하고 DNA 염기서열 분석에의 응용 및 DNA 염기서열 결정을 위한 새로운 전략 및 최근연구 동향에 대해 기술하였다.

• BMB Reports
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• v.29 no.3
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• pp.236-240
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• 1996

A 23-kDa molecular mass of antioxidant protein was purified from human liver. This protein exhibited the preventive effect against the inactivation of glutamine synthetase by a metal-catalyzed oxidation system. This antioxidant activity was supported by a thiol-reducing equivalent such as dithiothreitol in a similar manner to that of the 25-kDa thiol-specific antioxidant protein (TSA) from human red blood cells (HR). However, a thioredoxin-linked peroxidase activity of thiol-specific antioxidant protein of human liver (HLTSA) (0.91 ${\mu}mol/min/nmol$ of HLTSA) was much lower than that of thiol-specific antioxidant protein of human red blood cells (HRTSA) (16.4 ${\mu}mol/min/nmol$ of HRTSA). This HLTSA is also immnologically distinct from HRTSA Amino acid sequences of the three tryptic peptides (P1, P2, P3) of HLTSA were found to be completely homologous to segments of the known Mer5-like protein, which belongs to the known TSA family.