• 제목/요약/키워드: Modification of $S_e$

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Chemical Modification of Yeast Farnesyl Protein Transferase Expressed in E. coli

  • Kim, Hyun-Kyung;Yang, Chul-Hak
    • Bulletin of the Korean Chemical Society
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    • 제27권4호
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    • pp.529-534
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    • 2006
  • Chemical modification of the S. cerevisiae farnesyl protein transferase (FPT) with CMC, phenylglyoxal and DEPC resulted in enzyme inactivation, depending upon the reagent concentration. The peptide substrate GST-PEP-I, a GST-fused undecapeptide mimicking the C-terminus of $p21^{Ki-ras}$, protected the enzyme against inactivation by CMC which is specific to either aspartate or glutamate, while the other substrate farnesyl pyrophosphate (FPP) showed protection against phenylglyoxal which is the specific modifier of arginine residues, dependent on the substrate concentrations. Neither of the two substrates protected the enzyme against histidine inactivation by DEPC. It is suggested that there is at least one aspartate or glutamate residue at the peptide substrate binding site, and that at least one arginine residue is located at the binding site of FPP. There also seems to be at least one histidine residue which is critical for enzymic activity and is exposed toward the bulk solution, excluded from the substrate binding sites.

[ $\b{S}afety\;\b{A}nd\;\b{E}fficacy$ ] of $\b{K}orean$ red ginseng Intervention (SAEKI) Trial: Rationale, Design, and Expected Findings

  • Sievenpiper John L;Buono Marco Di;Stavro P. Mark;Jenkins Alexandra L;Nam Ki Yeul;Choi Melody;Naeem Asima;Leiter Lawrence A;Sung Mi-Kyung;Vuksan Vladimir
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2002년도 학술대회지
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    • pp.424-455
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    • 2002
  • Diabetes mellitus is reaching epidemic proportions worldwide. The insufficiency of medication to cope with this burden has coincided with a dramatic rise in the prevalence of use of complementary and alternative therapies, especially herbal treatments. This surge in demand presents a challenge to prove the safety and efficacy of these treatments in diabetes. Korean red ginseng (steam treated Panax ginseng C.A. Meyer) is a strong candidate to succeed. It has been shown to possess a multitude of hypoglycemic effects and improve metabolic disturbances related to diabetes in in vitro and animal models. Data in humans is also emerging to support these benefits. Whether these results can be replicated in a rigorous clinical testing program is unclear. We therefore investigated the antidiabetic effects of Korean red ginseng in a series of 2 acute and 1 longterm randomized, double-blinded, placebo-controlled clinical trials. This paper provides the rationale for this program of study, expanding on the problem of diabetes, its management, and the possible role for Korean red ginseng. It then describes the design and expected findings.

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The Mitochondrial Tricarboxylate Carrier of Silver Eel: Chemical Modification by Sulfhydryl Reagents

  • Capobianco, Loredana;Impagnatiello, Tecla;Ferramosca, Alessandra;Zara, Vincenzo
    • BMB Reports
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    • 제37권5호
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    • pp.515-521
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    • 2004
  • The tricarboxylate (or citrate) carrier was purified from eel liver mitochondria and functionally reconstituted into liposomes. Incubation of the proteoliposomes with various sulfhydryl reagents led to inhibition of the reconstituted citrate transport activity. Preincubation of the proteoliposomes with reversible SH reagents, such as mercurials and methanethiosulfonates, protected the eel liver tricarboxylate carrier against inactivation by the irreversible reagent N-(1-pyrenyl)maleimide (PM). Citrate and L-malate, two substrates of the tricarboxylate carrier, protected the protein against inactivation by sulfhydryl reagents and decreased the fluorescent PM bound to the purified protein. These results suggest that the eel liver tricarboxylate carrier requires a single population of free cysteine(s) in order to manifest catalytic activity. The reactive cysteine(s) is most probably located at or near the substrate binding site of the carrier protein.

Analysis of S-glutathionylated proteins during adipocyte differentiation using eosin-glutathione and glutaredoxin 1

  • Hwang, Sungwon;Iram, Sana;Jin, Juno;Choi, Inho;Kim, Jihoe
    • BMB Reports
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    • 제55권3호
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    • pp.154-159
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    • 2022
  • Protein S-glutathionylation is a reversible post-translational modification on cysteine residues forming a mixed disulfide with glutathione. S-glutathionylation, not only protects proteins from oxidation but also regulates the functions of proteins involved in various cellular signaling pathways. In this study, we developed a method for the detection of S-glutathionylated proteins (ProSSG) using eosin-glutathione (E-GSH) and mouse glutaredoxin 1 (mGrx1). ProSSG was efficiently and specifically labeled with E-GSH to form ProSSG-E via thiol-disulfide exchange. ProSSG-E was readily luminescent allowing the detection of ProSSG with semi-quantitative determination. In addition, a deglutathionylation enzyme mGrx1 specifically released E-GSH from ProSSG-E, which increased fluorescence allowing a sensitive determination of ProSSG levels. Application of the method to the adipocyte differentiation of 3T3-L1 cells showed specific detection of ProSSG and its increase upon differentiation induction, which was consistent with the result obtained by conventional immunoblot analysis, but with greater specificity and sensitivity.

Facilitation of SUMO (Small Ubiquitin-like Modifier) Modification at Tau 340-Lys Residue (a Microtubule-associated Protein) through Phosphorylation at 214-Ser Residue

  • Lee, Eun-Jeoung;Hyun, Sung-Hee;Chun, Jae-Sun;Ahn, Hye-Rim;Kang, Sang-Sun
    • Animal cells and systems
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    • 제11권1호
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    • pp.39-50
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    • 2007
  • Tau plays a role in numerous neuronal processes, such as vesicle transport, microtubule-plasma membrane interaction and intracellular localization of proteins. SUMO (Small Ubiquitin-like Modifier) modification (SUMOylation) appears to regulate diverse cellular processes including nuclear transport, signal transduction, apoptosis, autophagy, cell cycle control, ubiquitin-dependent degradation, as well as gene transcription. We noticed that putative SUMOylation site is localized at $^{340}K$ of $Tau(^{339}VKSE^{342})$ with the consensus sequence information (${\Phi}KxE$ ; where ${\Phi}$ represents L, I, V or F and x is any amino acid). In this report, we demonstrated that $^{340}K$ of Tau is the SUMOylation site and that a point mutant of Tau S214E (an analog of the phospho $^{214}S$ Tau) promotes its SUMOylation at $^{340}K$ and its nuclear or nuclear vicinity localization, by co-immunoprecipitation and confocal microscopy analysis. Further, we demonstrate that the Tau S214E (neither Tau S214A nor Tau K340R) mutant increases its protein stability. However, the SUMOylation at $^{340}K$ of Tau did not influence cell survival, as determined by FACS analysis. Therefore, our results suggested that the phosphorylation of Tau on $^{214}S$ residue promotes its SUMOylation on $^{340}K$ residue and nuclear vicinity localization, and increases its stability, without influencing cell survival.

Cross-cultural Validation of Instruments Measuring Health Beliefs about Colorectal Cancer Screening among Korean Americans

  • Lee, Shin-Young;Lee, Eunice E.
    • 대한간호학회지
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    • 제45권1호
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    • pp.129-138
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    • 2015
  • Purpose: The purpose of this study was to report the instrument modification and validation processes to make existing health belief model scales culturally appropriate for Korean Americans (KAs) regarding colorectal cancer (CRC) screening utilization. Methods: Instrument translation, individual interviews using cognitive interviewing, and expert reviews were conducted during the instrument modification phase, and a pilot test and a cross-sectional survey were conducted during the instrument validation phase. Data analyses of the cross-sectional survey included internal consistency and construct validity using exploratory and confirmatory factor analysis. Results: The main issues identified during the instrument modification phase were (a) cultural and linguistic translation issues and (b) newly developed items reflecting Korean cultural barriers. Cross-sectional survey analyses during the instrument validation phase revealed that all scales demonstrate good internal consistency reliability (Cronbach's alpha=.72~.88). Exploratory factor analysis showed that susceptibility and severity loaded on the same factor, which may indicate a threat variable. Items with low factor loadings in the confirmatory factor analysis may relate to (a) lack of knowledge about fecal occult blood testing and (b) multiple dimensions of the subscales. Conclusion: Methodological, sequential processes of instrument modification and validation, including translation, individual interviews, expert reviews, pilot testing and a cross-sectional survey, were provided in this study. The findings indicate that existing instruments need to be examined for CRC screening research involving KAs.

외란관측기를 이용한 영구자석 동기전동기에 대한 참조모델 견실적응 제어기의 성능개선 (Performance Enhancement of RMRAC Controller for Permanent Magnet Synchronous Motor using Disturbance Observer)

  • 김홍철;임훈;이장명
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.67-69
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    • 2007
  • PMSM (Permanent Magnet Synchronous Motor) current control is a most inner loop of electromechanical driving systems and it plays a foundation role in the hierarchy's control loop of several mechanical machine systems. In this paper, a simple RMRAC control scheme for the PMSM is proposed in the synchronous frame. In the synchronous current model, the input signal is composed of as a calculated voltage by adaptive laws and system disturbances. The gains of feed-forward and feed-back controller are estimated by the proposed e-modification methods respectively, where the disturbances are assumed as filtered current tracking errors. After the estimation of the disturbances from the tracking errors, the corresponding voltage is fed forward to control input to compensate for the disturbances. The proposed method is robust to high frequency disturbances and has a fast dynamic response to time varying reference current trajectory. It also shows a good real-time performance duo to it's simplicity of control structure. Through the simulations considering several cases of external disturbances and experimental results, efficiency of the proposed method is verified

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유리기판에 O2 플라즈마 표면처리 후 제작된 ITO 박막의 특성 (Characteristics of ITO Films Grown on an Oxygen Plasma Treated Glass Substrate)

  • 채홍철;홍주화
    • 대한금속재료학회지
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    • 제50권7호
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    • pp.545-548
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    • 2012
  • The optical and electronic properties of Indium Tin Oxide (ITO) thin films deposited on a RF-plasma treated glass substrate were investigated by X-Ray Photoelectron Spectroscopy (XPS), Ultra-violet Photoelectron Spectroscopy (UPS), Reflected Electron Energy Loss Spectroscopy (REELS). The modification of glass substrates was carried out by varying the time of the plasma surface treatment in an oxygen atmosphere. The focus of this research was to examine how the optical and electronic properties of ITO thin films change with the plasma treatment time. The surface energy increased since the carbon bonds were removed from the surface after the glass substrate received the surface treatment. The ITO thin films produced on the glass substrate with surface treatment showed that the high optical transmittance was approximately 85%. The measured band gap energy was as high as 3.23 eV when the plasma treatment time was 60 s and the work function after the treatment was increased by 0.5 eV in comparison to that before the treatment of 60 s. The ITO thin film exhibited an excellent sheet resistance of $2.79{\Omega}/{\Box}$. We found that the optical and electronic properties of ITO thin films can be improved by RF-plasma surface treatment.

패션일러스트레이션에서의 데페이즈망 표현기법에 대한 연구 (A Study on the Expressive Characteristics of Dépaysement in Fashion Illustration)

  • 김순자
    • 한국의상디자인학회지
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    • 제12권2호
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    • pp.21-39
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    • 2010
  • The purpose of this study is to develop a creative technique in fashion illustration through analyzing expressive characteristics of $d{\acute{e}}paysement$. This study is analyzed by examining the general theories of $d{\acute{e}}paysement$ and investigating the expressive technique related to the method of $d{\acute{e}}paysement$ in surrealism art and the expressive characteristics which is applied to fashion illustration. In this study, the researcher examines cases of the application of $d{\acute{e}}paysement$ to the fashion illustration through reviewing fashion illustrators' art works created since 2000. $D{\acute{e}}paysement$ is unfamiliar impression with lexical meaning in french that is translated by transposition or displacement technique, or country and one's home leave or person put in strange living environment. The characteristics of $d{\acute{e}}paysement$ in fashion illustration include spatial distortion, combination of heterogeneous objects located anywhere odd and modification and conversion of objects such as material change, change-over of scale in usual objects and conversion of inanimate objects into organism. As a result of reviewing the expressive characteristics of Depaysement from fashion illustration artworks, it is found that the fashion illustration with $d{\acute{e}}paysement$ fortified the individuality in fashion illustration and helps produce a creative inspiration which results in a distinctive ideas. This also has a greate possibilities to produce a tremendous ideas in fashion illustration.

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