• Title/Summary/Keyword: cytosol

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Inhibitory Activities of Three Compounds from Mucuna birdwoodiana on $3{\alpha}-Hydroxysteroid\;dehydrogenase$ (계혈등(Mucuna birdwoodiana)의 $3{\alpha}-Hydroxysteroid\;dehydrogenase$억제 성분)

  • Kwon, Yong-Soo;Lee, Jin-Hun;Kim, Chang-Min
    • Korean Journal of Pharmacognosy
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    • v.30 no.2
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    • pp.216-221
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    • 1999
  • The NAD(P)-linked $3{\alpha}-Hydroxysteroid$ $dehydrogenase(3{\alpha}-HSD)$ of rat liver cytosol is powerfully inhibited by the non-steroidal anti-inflammatory drugs in rank-order of their therapeutic potency, and this observation has now been developed into a rapid screen for predicting the potency of products that show anti-inflammatory effect. Five-plants were screened by using this method. Among them, BuOH-fraction of Mucuna birdwoodiana showed strong inhibitory effect on $3{\alpha}-HSD$, and three isoflavone compounds were isolated. Inhibitory activates of isolated compounds were compared.

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Refolding of Acid-Unfolded Globin to Hemoglobin

  • Lee Jong-Woo
    • Biomedical Science Letters
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    • v.11 no.1
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    • pp.85-88
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    • 2005
  • Hemoglobin is oxygen carrier protein within erythrocyte in blood. Apoprotein of this, globin, is synthesized in the cytosol but it's cofactor, heme, is synthesized in the mitochondria. It has not been known very well how globin receives the heme from mitochondria and folds to hemoglobin. In this folding process, the initial structure of globin seems to be very important. A small volume of globin at acid pH was added rapidly into the bulk of an egg phosphatidylcholine $60\%$ liposome, containing hemins, at neutral pH according to the Rapid Dilution method. It was observed that an acid-induced unfolding structure of globin is initially needed to receive hemins from the lipid bilayer of liposomes. Also, this conclusion was confirmed with the absorption spectrum of the refolded globin separated by centrifugation.

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Nucleotide Binding Component of the Respiratory Burst Oxidase of Human Neutrophils

  • Park, Jeen-Woo;Ahn, Soo-Mi
    • BMB Reports
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    • v.28 no.3
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    • pp.275-280
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    • 1995
  • The respiratory burst oxidase of neutrophils is a multicomponent enzyme, domant in resting cells, that catalyzes the reduction of oxygen to $O_{2}^{-}$ at the expense of NADPH. In the resting neutrophil, some of the components of the oxidase, including proteins p47 and p67, are in the cytosol, while the rest are in the plasma membrane. Recent evidence has suggested that at least some of the cytosolic oxidase components exist as a complex. The cytosolic complex with a molecular weight of ~240 kDa was found to bind to blue-agarose and 2',5'-ADP-agarose, which recognize nucleotide requiring enzymes. In order to identify the nucleotide binding component of the cytosolic complex we purified recombinant p47 and p67 fusion proteins using the pGEX system. Pure recombinant p47 was retained completely on 2',5'-ADP-agarose, whereas pure recombinant p67 did not bind to these affinity beads. On the basis of these results, we infer that p47 may contain the nucleotide binding site.

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Effect of Menhaden Oil Feeding on Protein Kinase C Activity and Membrane Phospholipid Profiles in Mouse Epidermal Cells (지방질원으로서 어유가 백서 상피세포의 인지질 조성 및 Protein Kinase C 활성에 미치는 영향)

  • Choe, Myeon
    • Journal of Nutrition and Health
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    • v.27 no.5
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    • pp.419-428
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    • 1994
  • To investigate the effect of dietary menhaden oil on protein kinase C (PKC) activity and membrane phospholipid composition in epidermal cells, female BALB/C mice were fed either menhaden oil or corn oil with two different levels(5% or 20%) for 6 weeks. Membrane phosphatidycholine(PC) was decreased in menhaden oil-fed group. Eicosapentaenoic acid(EPA) and Docosahexaenoic acid(DHA) were only presented in the acyl chain of membrane phospholipid of menhaden oil-fed mice, so that membrane fluidity of the group could be different from the other group. Both cytosolic and membrane-associated PKC activity in epidermal cells were decreased in menhaden oil-fed mice when compare with corn oil-fed mice. Furthermore, rate of PKC transfer from cytosol to membrane in menhaden oil-fed group was not as fast as in corn oil-fed group. Based on these observations, dietary menhaden oil might act differently from other dietary fat in carcinogenesis.

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"25-kDa Thiol Peroxidase" (TPx II) Acts as a "Housekeeping" Antioxidant

  • Cha, Mee-Kyung;Kim, II-Han
    • BMB Reports
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    • v.32 no.5
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    • pp.506-510
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    • 1999
  • The newly-found thiol peroxidases (TPx) with a conserved cysteine as the primary site of catalysis are capable of catalyzing the thiol-dependent reduction of peroxides. However, the cellular distributions of the isoforms remain poorly understood. As a first step in understanding the physiological functions of the TPx isoforms, we examined the cellular and tissue distribution of the isoenzymes in various bovine tissues. The tissue distributions of TPx isoenzymes indicate that two types of TPx are widely distributed throughout all of the tested tissues. These two forms are the predominant proteins, with levels of the proteins being quite different from each other. The level of predominant TPx proteins, named type II (TPx II) and type V (TPx V), appeared to be very different with respect to tissue type. The cellular distribution and level of TPx isoenzymes also varied with the types of cells. Immunoblot analysis of the mitochondrial and cytosol fractions from various tissues indicates that TPx III is a unique mitochondrial form. Based on the different tissue and cellular distribution of TPx isoenzymes, we discuss the physiological function of TPx isoenzymes, especially the ubiquitous TPx II.

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Glutathione Depletion by L-Buthionine-S,R-Sulfoximine Induces Apoptosis of Cardiomyocytes through Activation of PKC-δ

  • Kim, Young-Ae;Kim, Mi-Young;Jung, Yi-Sook
    • Biomolecules & Therapeutics
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    • v.21 no.5
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    • pp.358-363
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    • 2013
  • In the present study, we investigated the effect of intracellular glutathione (GSH) depletion in heart-derived H9c2 cells and its mechanism. L-buthionine-S,R-sulfoximine (BSO) induced the depletion of cellular GSH, and BSO-induced reactive oxygen species (ROS) production was inhibited by glutathione monoethyl ester (GME). Additionally, GME inhibited BSO-induced caspase-3 activation, annexin V-positive cells, and annexin V-negative/propidium iodide (PI)-positive cells. Treatment with rottlerin completely blocked BSO-induced cell death and ROS generation. BSO-induced GSH depletion caused a translocation of PKC-${\delta}$ from the cytosol to the membrane fraction, which was inhibited by treatment with GME. From these results, it is suggested that BSO-induced depletion of cellular GSH causes an activation of PKC-${\delta}$ and, subsequently, generation of ROS, thereby inducing H9c2 cell death.

Studies on the Intracellular Localization of Polyamines and Their related Enzymes in Spinach Leaves (Polyamine과 Polyamine의 생합성에 관련된 효소들의 시금치잎 세포내 분포에 관한 연구)

  • 김성호
    • Journal of Plant Biology
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    • v.32 no.4
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    • pp.285-292
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    • 1989
  • The intracellular localizations of polyamines and their related enzymes were investigated from young spinach leaves. Polyamines were present in all parts of plant cells, both in the subcellular organelles and in the soluble fraction of cytoplasm, however, polyamines were mainly located in the cytosolic fraction. Most activities of L-arginine decarboxylase(ADC) and L-ornithine decarboxylase(ODC), two important enzymes of putrescine and polyamine biosynthesis, were detected in cytosol fraction, while in subcellular organelles the activities were very low. Activities of diamine oxidase(DAO) and polyamine oxidase(PAO), the catabolic enzyme of diamine and polyamine, were not detected in spinach leaves. It was suggested that polyamines and their related synthetic enzymes were located in the soluble fraction of cytoplasm.

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Soluble Expression and Purification of Human Tissue-type Plasminogen Activator Protease Domain

  • Lee, Hak-Joo;Im, Ha-Na
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2607-2612
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    • 2010
  • Human tissue-type plasminogen activator (tPA) is a valuable thrombolytic agent used to successfully treat acute myocardial infarction, thromboembolic stroke, peripheral arterial occlusion, and venous thromboembolism. Recombinant tPA is accumulated as an inactive form in inclusion bodies of E. coli and is refolded in vitro, which is accompanied by extensive aggregation. In the present study, a tPA protease domain was expressed in an active soluble form in the cytosol of E. coli Rosetta-gami cells, which allowed disulfide bond formation and supplied the tRNA molecules required for six rarely used codons in E. coli. This strategy increased the amount of soluble protease domain protein and avoided the cumbersome refolding process. The purified protease domain not only degraded tPA substrate peptides but also formed a covalently bound complex with plasminogen activator inhibitor-1, as does full-length tPA. Soluble expression and purification of tPA domains may aid in functional analyses of this multi-domain protein, which has been implicated in many physiological and pathological processes.

Induction of Apoptotic Cell Death by a Ceramide Analog in PC-3 Prostate Cancer Cells

  • Oh, Ji-Eun;So, Kwang-Sup;Lim, Se-Jin;Kim, Mie-Young
    • Archives of Pharmacal Research
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    • v.29 no.12
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    • pp.1140-1146
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    • 2006
  • Ceramide analogs are potential chemotherapeutic agents. We report that a ceramide analog induces apoptosis in human prostate cancer cells. The ceramide analog induced cell death through an apoptotic mechanism, which was demonstrated by DNA fragmentation, the cleavage of poly ADP ribose polymerase (PARP), and a loss of membrane asymmetry. Treating the cells with ceramide analog resulted in the release of various proapoptotic mitochondrial proteins including cytochrome c and Smac/DIBLO into the cytosol, and a decrease in the mitochondrial membrane potential. In addition, the ceramide analog decreased the phospho-Akt and phospho-Bad levels. The expression of the antiapoptotic Bcl-2 decreased slightly with increasing Bax to Bcl-2 ratio. These results suggest that the ceramide analog induces apoptosis by regulating multiple signaling pathways that involve the mitochondrial pathway.

Inhibition of C-terminal O-Methyltransferase by a Rat Liver Cytosolic Peptide

  • Park, Seung-Hee;Lee, Hyang-Woo
    • Archives of Pharmacal Research
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    • v.17 no.5
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    • pp.354-359
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    • 1994
  • The activity of SD-framesylcysteine O-methyltransferase was assayed by incubating the enzyrne with a synthetic in vitro substrate, [N-acetyl-S-trans, trns-famesyl-L-cysteine (AFC)], together with S-adenosyl-L-[emthyl-$_{14}$C)ester(AFCME)], was then analyzed either directly on HPLC or by converting the AFC[$methyl^{14}C$]ME to [$methyl^{14}C$] aclcohol by basehydrolysis. Employing these two analytical methods, it was established that a peptide purifed from rat liver cytosol fraction [Int. J. Biochem., 25, 1157 919930] strongly inhibited the above enzyme activity with $IC_{50}\; of\; 7.1\times 10^{-8}$ M. Also, the S-famesylcysteine O-methyltransferase from several human colon cancer cells was equally inhibited by the peptide.

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