• Title/Summary/Keyword: Molecular genetics

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Solution Conformation of an Antimicrobial Peptide Gaegurin 4

  • Suk, Jae-Eun;Baek, Hwa-Jin;Lee, Byeong-Jae;Han, Kyou-Hoon
    • Proceedings of the Korean Biophysical Society Conference
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    • 1997.07a
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    • pp.13-13
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    • 1997
  • Gaegurin 4 is an antimicrobial peptide found in the skin of a Korean frog, Rana rugosa, known for its "wound-healing" effect for years. This 37-residue basic peptide binds to cell membranes and forms ion channels like other antimicrobial peptides but does not exhibit hemolytic activity.(omitted)

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Macrophage Migration Inhibitory Factor (MIF) Interacts with Bim and Inhibits Bim-mediated Apoptosis

  • Liu, Lingfeng;Chen, Jinzhong;Ji, Chaoneng;Zhang, Jiayi;Sun, Junlei;Li, Yao;Xie, Yi;Gu, Shaohua;Mao, Yumin
    • Molecules and Cells
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    • v.26 no.2
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    • pp.193-199
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    • 2008
  • The pro-apoptotic Bcl-2 family member Bim acts as a sensor for apoptotic stimuli and initiates apoptosis through the mitochondrial pathway. To identify novel regulators of Bim, we employed the yeast two-hybrid system and isolated the human gene encoding macrophage migration inhibitory factor (MIF), a ubiquitously expressed proinflammatory mediator that has also been implicated in cell proliferation, the cell cycle and carcinogenesis. The interaction between MIF and Bim was confirmed by both in vitro and in vivo protein interaction assays. Intriguingly, protein complexes between MIF and the three major Bim isoforms (BimEL/BimL/BimS) could be detected in HEK293 and K562 cells, especially in cells undergoing apoptosis. Moreover, exogenous expression of MIF partially inhibited Bim-induced apoptosis in HEK293 cells. SiRNA-mediated knockdown of MIF increased apoptosis in K562 cells exposed to the chemical oxidant diamide. Endogenous MIF may regulate the pro-apoptotic activity of Bim and inhibit the release of cytochrome c from mitochondria.

Molecular Characterization of the Ocular EST Clones from Olive Flounder, Paralichthys olivaceus

  • Lee, Jeong-Ho;Noh, Jae-Koo;Kim, Hyun-Chul;Park, Choul-Ji;Min, Byung-Hwa;Ha, Su-Jin;Park, Jong-Won;Kim, Young-Ok;Kim, Jong-Hyun;Kim, Kyung-Kil;Kim, Woo-Jin;Myeong, Jeong-In
    • Development and Reproduction
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    • v.14 no.2
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    • pp.107-113
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    • 2010
  • The olive flounder (Paralichthys olivaceus) is one of the most widely cultured flatfish in Korea and Japan. During development, in a process known as metamorphosis, this fish reorients itself to lie on one side, the body flattens, and the eye migrates to the other side of the body. However, few studies have focused on molecule regulation mechanism of eye development in olive flounder. To reveal the molecular mechanism of eye development, we performed the studies on identification of genes expressed in the eye of olive flounder using EST and RT-PCR strategy. A total of 270 ESTs were sequenced, and 178 (65.9%) clones were identified as known genes and 92 (34.1%) as unknown genes. Among the 178 EST clones, 29 (16.3%) clones were representing 9 unique genes identified as homologous to the previously reported olive flounder ESTs, 131 (73.6%) clones representing 107 unique genes were identified as orthologs of known genes from other organisms. We also identified a kind of eye development associated proteins, indicating EST as a powerful method for identifying eye development-related genes of fish as well as identifying novel genes. Further functional studies on these genes will provide more information on molecule regulation mechanism of eye development in olive flounder.

Individual-breed Assignment Analysis in Swine Populations by Using Microsatellite Markers

  • Fan, B.;Chen, Y.Z.;Moran, C.;Zhao, S.H;Liu, B.;Yu, M.;Zhu, M.J.;Xiong, T.A.;Li, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1529-1534
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    • 2005
  • Individual-breed assignments were implemented in six swine populations using twenty six microsatellites recommended by the Food and Agriculture Organization and the International Society for Animal Genetics (FAO-ISAG). Most microsatellites exhibited high polymorphisms as shown by the number of alleles and the polymorphism information content. The assignment accuracy per locus obtained by using the Bayesian method ranged from 33.33% (CGA) to 68.47% (S0068), and the accumulated assignment accuracy of the top ten loci combination added up to 96.40%. The assignment power of microsatellites based on the Bayesian method had positive correlations with the number of alleles and the gene differential coefficient ($G_{st}$) per locus, while it has no relationship to genetic heterozygosity, polymorphism information content per locus and the exclusion probabilities under case II and case III. The percentage of corrected assignment was highest for the Bayesian method, followed by the gene frequency and distancebased methods. The assignment efficiency of microsatellites rose with increase in the number of loci used, and it can reach 98% when using a ten-locus combination. This indicated that such a set of ten microsatellites is sufficient for breed verification purposes.

Novel Preparation and Characterization of the α4-loop-α5 Membrane-perturbing Peptide from the Bacillus thuringiensis Cry4Ba δ-endotoxin

  • Leetachewa, Somphob;Katzenmeier, Gerd;Angsuthanasombat, Chanan
    • BMB Reports
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    • v.39 no.3
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    • pp.270-277
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    • 2006
  • Helices 4 and 5 of the Bacillus thuringiensis Cry4Ba $\delta$-endotoxin have been shown to be important determinants for mosquito-larvicidal activity, likely being involved in membrane-pore formation. In this study, the Cry4Ba mutant protein containing an additional engineered tryptic cleavage site was used to produce the $\alpha4$-$\alpha5$ hairpin peptide by an efficient alternative strategy. Upon solubilization of toxin inclusions expressed in Escherichia coli and subsequent digestion with trypsin, the 130-kDa mutant protoxin was processed to protease-resistant fragments of ca. 47, 10 and 7 kDa. The 7-kDa fragment was identified as the $\alpha4$-loop-$\alpha5$ hairpin via N-terminal sequencing and mass spectrometry, and was successfully purified by size-exclusion FPLC and reversed-phase HPLC. Using circular dichroism spectroscopy, the 7-kDa peptide was found to exist predominantly as an $\alpha$-helical structure. Membrane perturbation studies by using fluorimetric calcein-release assays revealed that the 7-kDa helical hairpin is highly active against unilamellar liposomes compared with the 65-kDa activated full-length toxin. These results directly support the role of the $\alpha4$-loop-$\alpha5$ hairpin in membrane perturbation and pore formation of the full-length Cry4Ba toxin.

Optimization of Growth Medium and Fermentation Conditions for the Production of Laccase3 from Cryphonectria parasitica Using Recombinant Saccharomyces cerevisiae

  • Jeong, Yong-Seob;Sob, Kum-Kang;Lee, Ju-Hee;Kim, Jung-Mi;Chun, Gie-Taek;Chun, Jeesun;Kim, Dae-Hyuk
    • Mycobiology
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    • v.47 no.4
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    • pp.512-520
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    • 2019
  • Statistical experimental methods were used to optimize the medium for mass production of a novel laccase3 (Lac3) by recombinant Saccharomyces cerevisiae TYEGLAC3-1. The basic medium was composed of glucose, casamino acids, yeast nitrogen base without amino acids (YNB w/o AA), tryptophan, and adenine. A one-factor-at-a-time approach followed by the fractional factorial design identified galactose, glutamic acid, and ammonium sulfate, as significant carbon, nitrogen, and mineral sources, respectively. The steepest ascent method and response surface methodology (RSM) determined that the optimal medium was (g/L): galactose, 19.16; glutamic acid, 5.0; and YNB w/o AA, 10.46. In this medium, the Lac3 activity (277.04 mU/mL) was 13.5 times higher than that of the basic medium (20.50 mU/mL). The effect of temperature, pH, agitation (rpm), and aeration (vvm) was further examined in a batch fermenter. The best Lac3 activity was 1176.04 mU/mL at 25 ℃, pH 3.5, 100 rpm, and 1 vvm in batch culture.