• Applied Science and Convergence Technology
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• 제23권1호
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• pp.34-39
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• 2014

The programmable switches which control the delivery of electrical signals in programmable logic devices are fabricated using memory technology. Although phase change memory (PCM) technology is one of the most promising candidates for the manufacturing of the programmable switches, the threshold switching material should be added to a PCM cell for realization of the programmable switches based on PCM technology. In this work, we report the impurity-doped $Ge_2Sb_2Te_5$ (GST) chalcogenide alloy exhibiting threshold switching property. Unlike the GST thin film, the doped GST thin film prepared by the incorporation of In and P into GST is not crystallized even at the postannealing temperature higher than $200^{\circ}C$. This specific crystallization behavior in the doped GST thin film is attributed to the stabilization of the amorphous phase of GST by In and P doping.

• 미생물학회지
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• 제33권2호
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• pp.86-91
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• 1997

Pseudomonas sp. DJ77로부터 클로닝된 glutathione S-transferase 유전자(phnC)의 염기서열을 결정하였다. 603bp의 open reading frame(ORF)이 존재하였고 개시코돈 앞에서 Shine-Dalgarno sequence를, 종결코돈 뒤에서는 terminator sequence를 발견하였다. phnC 유전자에서 만들어지는 phnC 단백질은 21,416 Da으로 SDS-polyacrylamide gel 전기영동 결과와 일치하였다. PhnC는 Bulkholderia cepacia LB400, Cycloclasticus oligotrophus RB1의 GST와 각각 53.7%, 49%의 높은 상동성을 나타냈다. 아미노산 서열의 상동성과 필수잔기들의 존재유무로 판단할 때 PhnC GST는 theta class GSTs와 진화적으로 유연관계가 높았지만 alpha, mu, pi, sigma class GSTs에서 구조적, 기능적으로 중요하다고 알려진 아미노산 잔기들이 PhnC GST에도 보존되어 있었다. 또한, phnC 유전자의 위치가 C. oligotrophus RB1, B. cepacia LB400 등의 GST 유전자 위치와 유사하다는 점에서 PhnC 효소는 난분해성 방향족 탄화수소의 분해에 관여하는 것으로 생각된다.

• BMB Reports
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• 제56권8호
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• pp.457-462
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• 2023

Glutathione S-transferase omega 1 (GstO1) is closely associated with various human diseases, including obesity and diabetes, but its functional mechanism is not fully understood. In the present study, we found that the GstO1-specific inhibitor C1-27 effectively suppressed the adipocyte differentiation of 3T3-L1 preadipocytes. GstO1 expression was immediately upregulated upon the induction of adipocyte differentiation, and barely altered by C1-27. However, C1-27 significantly decreased the stability of GstO1. Moreover, GstO1 catalyzed the deglutathionylation of cellular proteins during the early phase of adipocyte differentiation, and C1-27 inhibited this activity. These results demonstrate that GstO1 is involved in adipocyte differentiation by catalyzing the deglutathionylation of proteins critical for the early phase of adipocyte differentiation.

• Journal of Plant Biotechnology
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• 제4권3호
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• pp.117-122
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• 2002

Cotton Glutathione S-Transferase(GST: EC 2.5.1.18) was cloned and Gh-5 cDNA was overexpressed in tobacco (Nicotiana tabacum) plants. The transformation of cotton GST in tobacco plant was confirmed by northern blot analysis. Type I and Type II transcript patterns were identified in Gh-5 transgenic tobacco plants. Type I transcripts was only discussed in this paper. Glutathione and 1-chloro-2,4-dinitrobenzene (CDNB) were used as the substrates, and the activity of GST in the type I transgenic plants was about 2.5-fold higher than the non-expressers and wild type tobacco plants. The expression of cotton GST in tobacco plants proved that Gh-5 could be translated into functional protein. Type I transgenic plants produced functional GST in the cells. Type I showed higher GST specific activity than Type II in the transgenic plants. Control and transgenic seedlings were grown in the growth chamber and under the light at 15$^{\circ}C$, and the effects of cotton GST in the seedlings was evaluated. The growth rate of Gh-5 overexpressors was better than the control and non-transgenic tobacco plants. Salinity tolerance was also analyzed on the seeds of transgenic plants. Seeds of Gh-5 overexpressors and the wild type tobacco seedlings were germinated and grown at 0, 50, 100, 150, and 200 mM NaCl solution. Gh-5 transgenic seedlings showed higher growth rate over control seedlings at both 50 and 100 mM NaCl solution. But at 0, 150, and 200 mM NaCl concentration, the difference in growth rate was not detected.

• 한국환경성돌연변이발암원학회지
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• 제24권2호
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• pp.73-78
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• 2004

In order to understand the mechanism of the regulation of drug metabolizing enzyme gene expression, we have studied the induction of CYP1A1 and GST$\alpha$, $\mu$, $\pi$ enzymes in Japanese monkey and rhesus monkey after the treatment with 3-methylcholanthrene (3MC) and di-n- butyl phthalate (DBP) and bisphenol A (BPA). The levels of mRNA were measured by RT-PCR in brain, intestine and liver. In the case of adult monkey, treatment with 3MC induced CYP1A1 mRNA in liver by 10-fold. The treatment with DBP induced CYP1A1 mRNA. Effects of 3MC and DBP on GST mRNA expression was not clear. But GST$\mu$ was slightly inhibited by the treatment with 3MC and DBP. GST$\pi$ was not induced by the treatment with 3MC and DBP in liver. GST$\alpha$ was slightly induced by the treatment with 3MC and DBP in liver. In the case of fetus monkey, the basal levels of fetus CYP1A1 mRNA and GSTs mRNA were relatively low compared to adult monkey. As the age of monkey increased, the basal levels of CYP1A1 mRNA were also increased. 3MC induced the expression of CYP1A1 mRNA in liver. The levels of GST$\mu$ and GST$\alpha$ were not changed by the treatment with 3MC and DBP. GST$\pi$ was slightly induced by the treatment with 3MC and DBP.

• 혜화의학회지
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• 제14권2호
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• pp.45-54
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• 2005

GST, an extract from 16 herbs, has been formulated and prescribed for the treatment of human rheumatoid arthritis(hRA) for many years. The present study was done to investigate whether GST has suppressive effects on activation of fibroblast-like sinoviocytes isolated from an RA patient. In tumor necrosis factor-a(TNF-a)/interleukin-1b(IL-1b) treated human sinoviocytes, The mRNA expression of molecular indicators related to pathologic changes of the sinoviocytes were examined using quantitative real-time PCR. The treatment of GST($100\;{\mu}g/ml$) suppressed the expression of proinflammatory cytokines and chemokines such as TNF-a, IL-1b, IL-6 and IL-8 compared with the control. The mRNA level of intracellular adhesion molecule-1(ICAM-1) which is known to increase in the activated sinoviocytes of RA patients, was slightly decreased by GST. The expression of NOS-II was considerably reduced, which was accompanied by a decrease in the production of nitric oxide(NO). In addition, GST considerably increased the mRNA levels of tissue inhibitors of matrix metalloproteinase-1(TIMP-1), while those of matrix metalloproteinase-3(MMP-3) were decreased. Taken together, these data suggested that GST might suppress the activation of sinoviocytes in hRA.

• Journal of Nutrition and Health
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• 제31권6호
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• pp.1014-1023
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• 1998

The influences of fish oil and different levels of vitamin I supplement on hepatocellular chemical carcinogenesis have been studied. Male Sprague-Dawley rats received diethylnitrosamine (DEN)(200mg/kg body weight) and were subjected to two-thirds partial hepatectomy to induce murine chemical hepatocarcinogenic procedure. Placental glutathione S-transferase(GST-P) positive foci area, antioxidant enzymes(Cu/Zn-superoxide dismutase(SOD), catalase, glutathione reductase (GR), total- glutathione peroxidase (TGPx), glutathione S -transferase (GST)), glucose 6-phosphatase (G6Pase) activities, and lipid peroxidation of microsomes(thiobarbituric acid reactive substances (TBARS)) were measured. Experimental animals were fed 15% corn or fish oil with 0, 40, 1,000, 10,000IU vitamin E /kg diet for 8 weeks. Vitamin E supplements decreased the area of GST-P positive foci in both groups. The higher the vitamin E levels, the smaller the area of GST-P positive foci were noticed. Compared to 0 IU vitamin E, 40 IU in corn oil and 1,000 IU in fish oil groups were effective in decreasing G57-P positive foci area. Fish oil groups tended to have smaller area of GST-P positive foci. fish oil groups showed lower body weight, lower activities of Cu/Zn-SOD and TGPx, higher TBARS contents, higher activities of GST, catalase, G6Pase, GR and higher liver/body ratio than corn oil groups. As the level of vitamin I increased, GST-P positive foci count, catalase activities, and TBARS tended to decrease. G6Pase activities tended to increase in both groups. At higher vitamin E levels, GST activities tended to decrease in fish oil groups. These results suggest that vitamin I has suppressive offects on hepatocellular chemical carcinogenesis probably through antioxidant eH:cts decreasing TBARS contents, $H_2O$$_2$, and organic peroxides. fish oil tended to have greated suppressive offects than corn oil on hepatocellular carcinogenesis. (Korean J Nutrition 31(6) : 1014-1023, 1998)

• Parasites, Hosts and Diseases
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• 제52권4호
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• pp.367-376
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• 2014

Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with $GRA2_{25-105}$, $GRA3_{39-138}$, $ROP2_{324-561}$, and $MIC2_{1-284}$ domains had respectively higher value of IgG avidity. The $rGST-GRA2_{25-105}$ and $rGST-GRA3_{39-138}$ were soluble, while $rGST-ROP2_{324-561}$ and $rGST-MIC2_{1-284}$ were not. $GRA2_{31-71}$, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The $rGST-GRA2_{31-71}-ROP2_{324-561}$, a chimeric protein, appeared to be soluble. Moreover, $rGST-GRA2_{31-71}-MIC2_{1-284}$ was also soluble and had higher IgG avidity comparing to $rGST-MIC2_{1-284}$. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1.

• BMB Reports
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• 제33권2호
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• pp.179-183
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• 2000

The glutathione S-transferase (GST) activities of S-type and L-type thioltransferases (TTases), which are purified from the seeds and leaves of Arabidopsis thaliana, respectively, were identified and compared. The S-type and L-type TTases showed $K_m$ values of 9.72 mM and 3.18mM on 1-chloro-2,4-dinitrobenzene (CDNB), respectively, indicating the L-type TTase has higher affinity for CDNB. The GST activity of the L-type TTase was rapidly inactivated after being heated at $70^{\circ}C$ or higher. The GST activity of the S-type TTase remains active in a range of $30-90^{\circ}C$. $Hg^{2+}$ inhibited the GST activity of the S-type TTase, whereas $Ca^{2+}$ and $Cd^{2+}$ inhibited the GST activity of the L-type TTase. Our results suggest that the GST activities of two TTases of Arabidopsis thaliana may have different catalytic mechanisms. The importance of the co-existence of TTAse and GST activities in one protein remains to be elucidated.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.282-282
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• 2011

Low power consuming operation of phase-change random access memory (PRAM) can be achieved by confining the switching volume of phase change media into nanometer scale. Ge2Sb2Te5 (GST) is one of the best materials for the phase change random access memory (PRAM) because the GST has two stable states, namely, high and low resistance values, which correspond to the amorphous and crystalline phases of GST, respectively. However, achieving the fast operation speed at lower current requires an alternative chalcogenide material to replace the GST and shrinking the dimension of programmable volume. In this paper, we have fabricated nanoscale contact area on Ge2Sb2Te5 thin films with trimming process. The GST material was fabricated by melt quenching method and the GST thin films were deposited with thickness of 100 nm by the electron beam evaporation system. As a result, the reset current can be safely scaled down by reducing the device contact area and we could confirmed the phase-change characteristics by applying voltage pulses.