• Title/Summary/Keyword: signal peptide

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Molecular Characterization of A Glycine and Proline-rich Antibacterial Protein from Larvae of A Beetle, Protaetia brevitarsis

  • Hwang, Jae-Sam;Kim, Seong-Ryul;Kang, Heui-Yun;Yun, Eun-Young;Ahn, Mi-Young;Park, Kwan-Ho;Jeon, Jae-Pil;Kim, Mi-Ae;Kim, Nam-Jung;Hwang, Seok-Jo;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.15 no.1
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    • pp.83-85
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    • 2007
  • A glycine and proline-rich antibacterial protein was cloned from larvae of a beetle, Protaetia brevitarsis. The DNAs encoded a deduced propeptide of 127 amino acid residues with predicted molecular weight of 14.0 kDa and PI of 7.89. Structural analysis of this protein indicated the presence of a recognition sequence for the cleavage site within the constitutive secretory pathway(Arg-Xaa-Lys/Arg-Arg), suggesting that mature portion(72 amino acid residues) is produced by cleavage of signal peptide and propeptide from 127 amino-acid-long precursor protein. Mature portion sequence of this protein showed 72% similarity to that of Oryctes rhinoceros Rhinocerosin and 91% to that of Holotrichia diomphalia holotricin 2. The mRNA expression was reached the highest level at 4 hrs after E. coli injection and then declined gradually.

Expression of Human Liver 3,4-Catechol estrogens UDP-Glucuronosyltransferase cDNA in COS 1 Cells

  • Ahn, Mee-Ryung;Owens, Ida-S.;Sheen, Yhun-Yhong
    • Archives of Pharmacal Research
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    • v.20 no.5
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    • pp.465-470
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    • 1997
  • The human cDNA clone UDPGTh2, encoding a liver UDP-glucuronosyltransferase (UDPGT), was isolated from a .gamma.gt 11 cDNA library by hybridization to mouse transferase cDNA clone, UDPGTm1. The two clones had 74% nlicleotide sequence identities in the coding region. UDPGTh2 encoded a 529 amino acid protein with an amino terminus membrane-insertion signal peptide and a carboxyl terminus membrane-spanning region. In order to establish substrate specificity, the clone was inserted into the pSVL vector (pUDPGTh2) and expressed in COS 1 cells. Sixty potential substrates were tested using cells transfected with pUDPGTh2. The order of relative substrate activity was as follows: 4-hydroxyestrone > estriol >2-hydroxyestriol > 4-hydroxyestradiol > $6{\alpha}$-hydroxyestradiol >$5{\alpha}$-androstane-$3{\alpha}$, $11{\beta}$, $17{\beta}$-triol=5${\beta}$-androstane-$3{\alpha}$ ${\beta}$, $17{\beta}$-triol. There were only trace amounts of gulcuronidation of 2-hydroxyestradiol and 2-hydroxyestrone, and in contrast to other cloned transferase, no gulcuronidation of either the primary estrogens and androgens (estrone, $17{\beta}$estradiol/testosterone, androsterone) or any of the exogenous substrates tested was detected. A lineweaver-Burk plot of the effect of 4-hydroxystrone concentration on the velocity of glucuronidation showed an apparent Km of $13{\mu}M$. The unique specificity of this transferase might play an important role in regulating the level and activity of these potent and active estrogen metabolites.

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Cloning of OLR1 Gene in Pig Adipose Tissue and Preliminary Study on Its Lipid-accumulating Effect

  • Sun, Chao;Liu, Chun-wei;Zhang, Zhong-pin
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.10
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    • pp.1420-1428
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    • 2009
  • In this study we cloned and characterized a novel lipid-accumulating gene, the oxidized low-density lipoprotein receptor 1 (OLR1), which is associated with lipogenesis. We analyzed the gene structure and detected the mRNA transcriptional expression levels in pig adipose tissues at different months of age (MA) and in different economic types (lean type and obese type) using real-time fluorescence quantitative PCR. OLR1 expression profile in different tissues of pig was analyzed. Finally, we studied the correlation between OLR1 and lipid metabolism related genes including peroxisome proliferator-activated $receptor{\gamma}2$ ($PPAR{\gamma}2$), fatty acid synthetase (FAS), triacylglycerol hydrolase (TGH), CAAT/enhancer binding protein $\alpha$ ($C/EBP{\alpha}$) and sterol regulatory element binding protein-1c (SREBP-1c). Results indicated that the OLR1 gene of the pig exhibited the highest homology with the cattle (84%), and the lowest with the mouse (27%). The signal peptide located from amino acid 38 to 60 and the domain from amino acid 144 to 256 were shared by the C-type lectin family. The expression level of OLR1 in pig lung was exceedingly higher than other tested tissues (p<0.01). In pig adipose tissue, the expression level of OLR1 mRNA increased significantly with growth (p<0.01). The expression level of OLR1 mRNA in obese-type pigs was significantly higher than that of lean-type pigs of the same monthly age (p<0.05). In adipose tissue, the expression of OLR1 correlated with $PPAR{\gamma}2$, FAS and SREBP-1c, but not TGH or C/EBP${\alpha}$. In conclusion, OLR1 was highly associated with fat deposition and its transcription, as suggested by high correlations, was possibly regulated by $PPAR{\gamma}2$ and SREBP-1c.

Cloning, Expression, and Characterization of Protease-resistant Xylanase from Streptomyces fradiae var. k11

  • Li, Ning;Yang, Peilong;Wang, Yaru;Luo, Huiying;Meng, Kun;Wu, Nigfeng;Fan, Yunliu;Yao, Bin
    • Journal of Microbiology and Biotechnology
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    • v.18 no.3
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    • pp.410-416
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    • 2008
  • The gene SfXyn10, which encodes a protease-resistant xylanase, was isolated using colony PCR screening from a genomic library of a feather-degrading bacterial strain Streptomyces fradiae var. k11. The full-length gene consists of 1,437bp and encodes 479 amino acids, which includes 41 residues of a putative signal peptide at its N terminus. The amino acid sequence shares the highest similarity (80%) to the endo-1,4-${\beta}$-xylanase from Streptomyces coelicolor A3, which belongs to the glycoside hydrolase family 10. The gene fragment encoding the mature xylanase was expressed in Escherichia coli BL21 (DE3). The recombinant protein was purified to homogeneity by acetone precipitation and anion-exchange chromatography, and subsequently characterized. The optimal pH and temperature for the purified recombinant enzyme were 7.8 and $60^{\circ}C$, respectively. The enzyme showed stability over a pH range of 4.0-10.0. The kinetic values on oat spelt xylan and birchwood xylan substrates were also determined. The enzyme activity was enhanced by $Fe^{2+}$ and strongly inhibited by $Hg^{2+}$ and SDS. The enzyme also showed resistance to neutral and alkaline proteases. Therefore, these characteristics suggest that SfXyn10 could be an important candidate for protease-resistant mechanistic research and has potential applications in the food industry, cotton scouring, and improving animal nutrition.

Functional Analysis of a Gene Encoding Endoglucanase that Belongs to Glycosyl Hydrolase Family 12 from the Brown-Rot Basidiomycete Fomitopsis palustris

  • Song, Byeong-Cheol;Kim, Ki-Yeon;Yoon, Jeong-Jun;Sim, Se-Hoon;Lee, Kang-Seok;Kim, Yeong-Suk;Kim, Young-Kyoon;Cha, Chang-Jun
    • Journal of Microbiology and Biotechnology
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    • v.18 no.3
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    • pp.404-409
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    • 2008
  • The brown-rot basidiomycete Fomitopsis palustris is known to degrade crystalline cellulose (Avicel) and produce three major cellulases, exoglucanases, endoglucanases, and ${\beta}$-glucosidases. A gene encoding endoglucanase, designated as cel12, was cloned from total RNA prepared from F. palustris grown at the expense of Avicel. The gene encoding Cel12 has an open reading frame of 732 bp, encoding a putative protein of 244 amino acid residues with a putative signal peptide residing at the first 18 amino acid residues of the N-terminus of the protein. Sequence analysis of Cel12 identified three consensus regions, which are highly conserved among fungal cellulases belonging to GH family 12. However, a cellulose-binding domain was not found in Cel12, like other GH family 12 fungal cellulases. Northern blot analysis showed a dramatic increase of cel12 mRNA levels in F. palustris cells cultivated on Avicel from the early to late stages of growth and the maintenance of a high level of expression in the late stage, suggesting that Cel12 takes a significant part in endoglucanase activity throughout the growth of F. palustris. Adventitious expression of cel12 in the yeast Pichia pastoris successfully produced the recombinant protein that exhibited endoglucanase activity with carboxymethyl cellulose, but not with crystalline cellulose, suggesting that the enzyme is not a processive endoglucanase unlike two other endoglucanases previously identified in F. palustris.

Antimicrobial Activity of Bacteriophage Endolysin Produced in Nicotiana benthamiana Plants

  • Kovalskaya, Natalia;Foster-Frey, Juli;Donovan, David M.;Bauchan, Gary;Hammond, Rosemarie W.
    • Journal of Microbiology and Biotechnology
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    • v.26 no.1
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    • pp.160-170
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    • 2016
  • The increasing spread of antibiotic-resistant pathogens has raised the interest in alternative antimicrobial treatments. In our study, the functionally active gram-negative bacterium bacteriophage CP933 endolysin was produced in Nicotiana benthamiana plants by a combination of transient expression and vacuole targeting strategies, and its antimicrobial activity was investigated. Expression of the cp933 gene in E. coli led to growth inhibition and lysis of the host cells or production of trace amounts of CP933. Cytoplasmic expression of the cp933 gene in plants using Potato virus X-based transient expression vectors (pP2C2S and pGR107) resulted in death of the apical portion of experimental plants. To protect plants against the toxic effects of the CP933 protein, the cp933 coding region was fused at its Nterminus to an N-terminal signal peptide from the potato proteinase inhibitor I to direct CP933 to the delta-type vacuoles. Plants producing the CP933 fusion protein did not exhibit the severe toxic effects seen with the unfused protein and the level of expression was 0.16 mg/g of plant tissue. Antimicrobial assays revealed that, in contrast to gram-negative bacterium E. coli (BL21(DE3)), the gram-positive plant pathogenic bacterium Clavibacter michiganensis was more susceptible to the plant-produced CP933, showing 18% growth inhibition. The results of our experiments demonstrate that the combination of transient expression and protein targeting to the delta vacuoles is a promising approach to produce functionally active proteins that exhibit toxicity when expressed in plant cells.

Molecular Characterization of a Thermophilic and Salt- and Alkaline-Tolerant Xylanase from Planococcus sp. SL4, a Strain Isolated from the Sediment of a Soda Lake

  • Huang, Xiaoyun;Lin, Juan;Ye, Xiuyun;Wang, Guozeng
    • Journal of Microbiology and Biotechnology
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    • v.25 no.5
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    • pp.662-671
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    • 2015
  • To enrich the genetic resource of microbial xylanases with high activity and stability under alkaline conditions, a xylanase gene (xynSL4) was cloned from Planococcus sp. SL4, an alkaline xylanase-producing strain isolated from the sediment of soda lake Dabusu. Deduced XynSL4 consists of a putative signal peptide of 29 residues and a catalytic domain (30-380 residues) of glycosyl hydrolase family 10, and shares the highest identity of 77% with a hypothetical protein from Planomicrobium glaciei CHR43. Phylogenetic analysis indicated that deduced XynSL4 is closely related with thermophilic and alkaline xylanases from Geobacillus and Bacillus species. The gene xynSL4 was expressed heterologously in Escherichia coli and the recombinant enzyme showed some superior properties. Purified recombinant XynSL4 (rXynSL4) was highly active and stable over the neutral and alkaline pH range from 6 to 11, with maximum activity at pH 7 and more than 60% activity at pH 11. It had an apparent temperature optimum of 70℃ and retained stable at this temperature in the presence of substrate. rXynSL4 was highly halotolerant, retaining more than 55% activity with 0.25-3.0 M NaCl and was stable at the concentration of NaCl up to 4M. The enzyme activity was significantly enhanced by β-mercaptoethanol and Ca2+ but strongly inhibited by heavy-metal ions and SDS. This thermophilic and alkaline- and salt-tolerant enzyme has great potential for basic research and industrial applications.

Effects of the Bee Venom on Human Gastric Adenocarcinoma Cell Lines (봉독이 위암 세포주에 미치는 효과)

  • Heo, Gyeong;Kim, Myung Ho;Lim, Seong Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.1
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    • pp.92-98
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    • 2013
  • Bee Venom(below BV) has been used in alternative medicine to treat the diseases, such as pain diseases. BV contains a variety of peptides, including melittin, apamin, adolapin, MCD peptide, enzymes(i.e. PLA2), amines(i.e. histamine and epinephrine), and nonpeptide components. The two main components of BV are melittin and PLA2. The cell cytotoxic effects through the activation of PLA2 by melittin have been suggested to be the critical mechanism for the depress of cancer cell. Melittin and PLA2 have been reported to induce apoptosis and to possess anti-cancer effects and neurite outgrowth in PC12 cells. Analysis of proliferation was confirmed by MTT assay. BV decreased cell number through dose- and duration-dependent manner and these effects are apparent at a concentration of 3 ${\mu}g/ml$. To observe which signaling molecules will be activated by BV, phosphorylation of ERK, p38 MAPK, JNK and ERM were examined by Western blot analysis. To study the long term effect of BV in human gastric adenocarcinoma cell lines, the image of cells treated with BV for 4 days were obtained. BV was shown to exhibit anti-cancer activity in human gastric adenocarcinoma cell lines at a broad range of concentrations of 3 ${\mu}g/ml$. ERK, p38 MAPK and JNK were found to increase in BV treated cells. However, ERM which known to be involved in the cell death, was gradually decreased to 30minutes after addition 3 ${\mu}g/ml$ of BV. These results provide a possible BV-induced inhibitory signal for cancer proliferation that is initiated by the decrease in ERM activity. Moreover, it is likely that the activation of ERK, p38 MAPK and JNK are required for the BV-induced inhibition of cancer proliferation.

Cloning, Expression, and Characterization of a Highly Active Alkaline Pectate Lyase from Alkaliphilic Bacillus sp. N16-5

  • Li, Gang;Rao, Lang;Xue, Yanfen;Zhou, Cheng;Zhang, Yun;Ma, Yanhe
    • Journal of Microbiology and Biotechnology
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    • v.20 no.4
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    • pp.670-677
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    • 2010
  • An alkaline pectate lyase, Bsp165PelA, was purified to homogeneity from the culture broth of alkaliphilic Bacillus sp. N16-5. The enzyme showed a specific activity as high as 1,000 U/mg and had optimum activity at pH 11.5 and $50^{\circ}C$. It was composed of a single polypeptide chain with a molecular mass of 42 kDa deduced from SDS-PAGE, and its isoelectric point was around pH 6.0. It could efficiently depolymerize polygalacturonate and pectin. Characterization of product formation revealed unsaturated digalacturonate and trigalacturonate as the main products. The pectate lyase gene (pelA) contained an open reading frame (ORF) of 1,089 bp, encoding a 36-amino acids signal peptide and a mature protein of 326 amino acids with a calculated molecular mass of 35.943 Da. The deduced amino acid sequence from the pelA ORF exhibited significant homology to those of known pectate lyases in polysaccharide lyase family 1. Some conserved active-site amino acids were found in the deduced amino acid sequence of Bsp165PelA. $Ca^{2+}$ was not required for activity on pectic substrates.

Molecular Cloning and Characterization of a Flower-specific Thionin in Chinese Cabbage

  • Jung, Bae-Gyo;Choi, Yeon-Ok;Lee, Kyun-Oh;Chi, Yong-Hun;Kang, Soon-Suk;Lee, Seung-Sik;Park, Soo-Kwon;Lee, Jung-Ro;Lim, Chae-Oh;Lee, Sang-Yeol
    • BMB Reports
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    • v.34 no.3
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    • pp.201-205
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    • 2001
  • Thionins are a family of low molecular weight cysteine-rich antimicrobial peptides. We isolated a cDNA encoding thionin gene from a flower bud cDNA library of Chinese cabbage (CFT). The gene contains 611 by nucleotides with 60 bp, and 150 by untranslated regions at its N- and C-terminal, respectively. The deduced amino acid sequence encoded 133 amino acids containing precursor polypeptide. The protein reveals that the precursor has a tripartite structure: a putative signal sequence at the N-terminus, followed by a mature thionin peptide, and a C-terminal acidic domain, which facilitates transport of the mature thionin through membrane. Genomic Southern blot analysis suggests that the CFT gene may be present as a single or two copy gene in the Chinese cabbage genome. Northern blot analysis shows that the gene is specifically expressed in flowers, but not in leaves, stems, or roots. When we analyzed the antifungal activity of the recombinant CFT protein, which was expressed in E. coli using the truncated cDNA region corresponding to the mature protein part, it was not active on fungal growth inhibition.

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