• Archives of Pharmacal Research
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• 제20권3호
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• pp.201-205
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• 1997

A very high content (at least 0.23%) of ergosterol peroxide was isolated from Naematoloma fasciculare Karst. Not only ergosterol peroxide but also ergosterol showed very strong anticomplementary activity on the classical pathway, the $IC_{50}$ values being $5.0 {\mu}M$ and $1.0 {\mu}M$, respectively. The $ ^{1}H $and $^{13}C$ NMR data of ergosterol peroxide were revised and completely assigned by DEPT, $^{1}H-^{1}H$ COSY, HMQC and HMBC correlations.

• Molecules and Cells
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• 제39권1호
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• pp.26-30
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• 2016

Peroxiredoxins are ubiquitous thiol proteins that catalyse the breakdown of peroxides and regulate redox activity in the cell. Kinetic analysis of their reactions is required in order to identify substrate preferences, to understand how molecular structure affects activity and to establish their physiological functions. Various approaches can be taken, including the measurement of rates of individual steps in the reaction pathway by stopped flow or competitive kinetics, classical enzymatic analysis and measurement of peroxidase activity. Each methodology has its strengths and they can often give complementary information. However, it is important to understand the experimental conditions of the assay so as to interpret correctly what parameter is being measured. This brief review discusses different kinetic approaches and the information that can be obtained from them.

• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.889-896
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• 2001

The reaction of gas-phase atomic bromine with highly covered chemisorbed hydrogen atoms on a silicon surface is studied by use of the classical trajectory approach. It is found that the major reaction is the formation of HBr(g), and it proceeds th rough two modes, that is, direct Eley-Rideal and hot-atom mechanism. The HBr formation reaction takes place on a picosecond time scale with most of the reaction exothermicity depositing in the product vibration and translation. The adsorption of Br(g) on the surface is the second most efficient reaction pathway. The total reaction cross sections are $2.53{\AA}2$ for the HBr formation and $2.32{\AA}2$ for the adsorption of Br(g) at gas temperature 1500 K and surface temperature 300 K.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.372.1-372.1
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• 2002

AIzelin (1) and quercitrin (2) isolated from the EtOAc-soluble fraction of the leaves of Litsea japonica Jussieu (Lauraceae) showed inhibitory activity against classical pathway complement system with 50% inhibitory concentration ($IC_{50}$/) values of 112.2 and 198.2 $\mu\textrm{g}$/$m\ell$. respectively. For the structure-activity relationship of flavonoids on anti-complement system. myricitrin (3) from JUQ/ans mandshurica Maximowicz (Juglandaceae) also tested anti-complement activity. while this was devoid of any significant activity. (omitted)

• 한국식품과학회지
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• 제40권2호
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• pp.220-227
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• 2008

한국 전통발효음료 중에 존재하는 특이다당류의 화학적 특성 및 생물활성을 규명할 목적으로, 농가에서 직접 발효한 감식초로부터 다당류를 분리하고 이들의 각종 면역증강활성에 대해 검토하였다. 감식초에 80% ethanol 침전을 행하여 얻어진 조다당 획분 PV-0을 이용, 연속적인 3회의 column chromatography를 행하여, 감식초의 주요 다당인 PV-1b-I으로 정제할 수 있었다. PV-1b-I획분은 HPLC상에서 대칭을 유지하는 단일 peak로 검출되었으며, 분자량은 약 110 kDa으로 평가되었다. 정제다당인 PV-1b-I의구성당 조성을 확인한 결과, mannose(46.8%), galactose(28.5%) 및 arabinose(19.1%)를 높은 비율로 함유하고 있었다. 또한 본 정제다당은 ${\beta}$-glucosyl Yariv reagent와 강하게 반응하는 특성을 보여주었으며 이러한 사실로부터 PV-1b-I이 arabino-3,6-galactan 부위를 소유함을 확인할 수 있었다. 한편 감식초에서 정제한 다당 PV-1b-I은 in vitro상에서 macrophage의 활성화를 높은 비율로 유도하였으며, 비장세포에 대해 높은 증식능을 보였다. 또한 PV-1b-I을 정맥 투여한 경우, NK cell을 활성화하여 YAC-1 종양세포에 대한 세포독성을 증가시킴이 관찰되었다. 한편 고분자 정제 다당인 PV-1b-I는 비특이적 면역계에 있어 중요 역할을 담당하고 있는 보체계에 대하여 농도 의존적인 활성화 경향을 보였다. 이들은 $Ca^{2+}$ 이온이 제거된 상태에서의 항보체 활성과 anti-human C3를 이용한 2차원 면역전기영동에 의하여 C3 산물을 동정한 결과로부터 보체계의 classical pathway와 alternative pathway 양 경로를 모두 경유하여 활성을 나타냄을 확인할 수 있었다.

• 대한의생명과학회지
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• 제20권4호
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• pp.250-255
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• 2014

Mycobacterium tuberculosis (MTB) resides and replicates inside macrophages. In our previous report, we reported that CD8+ T cell-mediated immune responses specific for the peptide derived from MTB RNA polymerase beta-subunit ($RpoB_{127-135}$) could be induced in TB patients expressing HLA-$A^*0201$ subtype. In order to examine whether $RpoB_{127-135}$ specific CD8+ T cells can recognize MTB infected macrophages in vitro, CD8+ T cell lines specific for $RpoB_{127-135}$ peptide were generated from peripheral blood mononuclear cells (PBMCs) of healthy HLA-$A^*0201$ subjects by in vitro immunization technique. In this study, we observed $RpoB_{127-135}$ specific CD8+ T cells could recognize and destroy macrophages infected with MTB for 2 to 4 days. $RpoB_{127-135}$ specific CD8+ T cell immune response was inducible from PBMC of healthy subjects expressing HLA-$A^*0206$ subtype, one of HLA-A2 supertype members. Next, we investigated the HLA-I processing mechanism of $RpoB_{127-135}$ peptide in MTB infected macrophages. As a result, the presentation of the MTB derived epitope peptide, $RpoB_{127-135}$, to CD8+ T cells was not inhibited by the treatment with brefeldin-A (ER-Golgi transport inhibitor) or lactacystin (proteasome inhibitor), which blocks the classical HLA-I processing pathway. However, $RpoB_{127-135}$ specific CD8+ T cell activity was blocked either by the blocking agent for the endocytosis (cytochalasin D) or by the blocking antibody (W6/32) for HLA-I molecules. Therefore, the $RpoB_{127-135}$ peptide may be processed by accessing the alternate HLA-I processing pathway. Understanding the processing and presentation mechanisms of the MTB derived proteins will help to improve the efficacy of vaccines and the efficiency of therapeutic agents for TB.

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.75-80
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• 2006

Biomarkers identify various stages and interactions on the pathway from exposure to disease. The three categories of biomarkers are those measuring susceptibility, exposure and effect. Susceptibility biomarkers are identifiable genetic variations affecting absorption, metabolism or response to environmental agents. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. The biomarker response is typical of chemical pollution by specific classes of compound, such as (i) heavy metals (mercury, cadmium, lead, zinc), responsible for the induction of metallothionein synthesis, and (ii) organochlorinated pollutants (PCBs, dioxins, DDT congeners) and polycyclic aromatic hydrocarbons (PAHs), which induce the mixed function oxygenase (MFO) involved in their bio transformations and elimination. Currently genomic researches are developed in human cDNA clone subarrays oriented toward the expression of genes involved in responses to xenobiotic metabolizing enzymes, cell cycle components, oncogenes, tumor suppressor genes, DNA repair genes, estrogen-responsive genes, oxidative stress genes, and genes known to be involved in apoptotic cell death. Several research laboratories in Korea for kicking off these Environmental Genomics were summarized.

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.205-214
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• 2002

The reaction of gas-phase atomic hydrogen with hydrogen atoms chemisorbed on a silicon surface is studied by use of the classical trajectory approach. Especially, we have focused on the mechanism changes with the hydrogen surface coverage difference. On the sparsely covered surface, the gas atom interacts with the preadsorbed hydrogen atom and adjacent bare surface sites. In this case, it is shown that the chemisorption of H(g) is of major importance. Nearly all of the chemisorption events accompany the desorption of H(ad), i.e., adisplacement reaction. Although much less important than the displacement reaction, the formation of $H_2(g)$ is the second most significant reaction pathway. At gas temperature of 1800 K and surface temperature of 300 K, the probabilities of these two reactions are 0.750 and 0.065, respectively. The adsorption of H(g) without dissociating H(ad) is found to be negligible. In the reaction pathway forming $H_2$, most of the reaction energy is carried by $H_2(g)$. Although the majority of $H_2(g)$ molecules are produced in sub-picosecond, direct-mode collisions, there is a small amount of $H_2(g)$ produced in multiple impact collisions, which is characteristic of complex-mode collisions. On the fully covered surface, it has been shown that the formation of $H_2(g)$ is of major importance. All reactive events occur on a subpicosecond scale, following the Eley-Rideal mechanism. At gas temperature of 1800 K and surface temperature of 300 K, the probability of the $H_2(g)$ formation reaction is 0.082. In this case, neither the gas atom trapping nor the displacement reaction has been found.

• BMB Reports
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• 제43권3호
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• pp.182-187
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• 2010

family (CMTM) is a novel family of proteins linking classical chemokines and the transmembrane 4 superfamily (TM4SF). Our earlier studies indicated several CMTM members (such as CKLF1 and CMTM2) have a secreted form. This is the first report of the secreted form of CMTM5-v1, the major RNA splicing form of CMTM5, which is produced as small vesicles (<100 nm diameter) and floats at a peak density of 1.19 g/ml on continuous sucrose gradients. CMTM5-v1 has no obvious co-localization with CD63 or Golgi complex. In addition, brefeldin A but not wortmannin can inhibit the secretion of CMTM5-v1. Our results suggest that CMTM5-v1 might be secreted via a different vesicle-mediated secretory pathway, which will be helpful for the studies of vesicle-mediated secretion and MARVEL domain-containing proteins.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2002년도 창립10주년기념 및 국립독성연구원 의약품동등성평가부서 신설기념 국재학술대회:생물학적 동등성과 의약품 개발 전략을 위한 국제심포지움
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• pp.89-96
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• 2002

The importance of apoptosis in normal development and pathogenesis has been well recognized, and explosive progress towards dissecting its commitment step has been made during the past decade. Mitochondria, Apaf-1, caspase, and bcl-2 family members play central roles in the commitment step. However, it is still unclear how upstream cell survival pathways regulate apoptosis. It is also unknown whether the bcl-2 family members have any effect on the upstream survival pathways. We have demonstrated that the anti-apoptotic gene product bcl-2 greatly induces expression of the tissue inhibitor of metalloproteinase-1 (TIMP-1) in human breast epithelial cells. Surprisingly, we found that TIMP-1, like bcl-2, is a potent inhibitor of apoptosis induced by a variety of stimuli. Functional studies indicate that TIMP-1 inhibits a classical apoptotic pathway mediated by caspases, and that focal adhesion kinase (FAK)/Pl 3-kinase and mitogen activated protein kinase (MAPK) are critical for TIMP- 1 -mediated cell survival. We also showed specific association of TIMP-1 with the cell surface. Consistently, a 150-H)a surface protein was identified in MCF10A cells that specifically binds TIMP-1. Taken together, we hypothesize that TIMP-I binding on the cell surface induces a cell survival pathway that regulates the common apoptosis commitment step. The results of these studies will address a new paradigm in the regulation of apoptosis by an extracellular molecule TIMP-1, and also greatly enhance our understanding of TIMP-1's pleiotropic activity in many physiological and pathological processes. This information may also be useful in designing more rational therapeutic interventions aimed at modulating the anti-apoptotic activity of TIMP-1 .