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The Stimulation of Arginine Decarboxylase Activity by alpha-Difluoromethyl$ Ornithine in Tobacco Suspension Cultured Cells

  • Lee, Sun-Hi;Kim, Yong-Bum;Lee, Myeong-Min;Park, Ki-Young
    • Journal of Plant Biology
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    • v.39 no.2
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    • pp.107-112
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    • 1996
  • To study the compensatory aspect of putrescine biosynthetic enzyme n tobacco suspension cultured cells, we examined the contents of the cellular polyamines and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17) in the tobacco suspension cells treated with $\alpha$-difluoromethyl arginine (DFMA) or $\alpha$-difluoromethyl ornithine (DFMO). In the untreated cells, the content of the cellular putrescine was decreased during the first 3 hours and then subsequently increased. However, the content of the cellular spermidine and spermine remained constant during the incubation time. While ADC activity increased after 6 hours, ODC activity decreased following the rapid increase until 6 hours. DFMA induced the decrease in the contents of putrescine and spermidine, and the increase in that of spermine. It also caused the inhibition of ADC and ODC activities throughout the incubation time. DFMO produced the stimulation of ADC activity about 2 times of untreated cells and the decrease in the content of putrescine about 50% of them at 12 hour. The application of putrescine or cycloheximide prevented the increase of ADC activity by DFMO but that of actinomycin-D did not show any detectable effect. The stimulation of ADC activity by DFMO in tobacco suspension cultured cells was probably due to the enhancement of de novo synthesis for ADC protein, which might be regulated in the translation step by the content of the cellular putrescine.

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Mercury Resistance and Removal Mechanisms of Pseudomonas sp. Isolated Mercury-contaminated Site in Taiwan

  • Luo, Kai-Hong;Chen, Ssu-Ching;Liao, Hung-Yu
    • Journal of Soil and Groundwater Environment
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    • v.21 no.5
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    • pp.16-24
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    • 2016
  • A new strain of Pseudomonas sp. was isolated from mercury (Hg)-contaminated sites in Taiwan. This bacterium removed more than 80% of Hg present in the culture medium at 12 h incubation and was chosen for further analysis of the molecular mechanisms of Hg tolerance/removal abilities in this Pseudomonas sp. We used RNA-seq, one of the next-generation sequencing methods, to investigate the transcriptomic responses of the Pseudomonas sp. exposed to 60 mg/L of Hg2+. We de novo assembled 4,963 contigs, of which 10,533 up-regulated genes and 5,451 down-regulated genes were found to be regulated by Hg. The 40 genes most altered in expression levels were associated with tolerance to Hg stress and metabolism. Functional analysis showed that some Hg-tolerant genes were related to the mer operon, sulfate uptake and assimilation, the enzymatic antioxidant system, the HSP gene family, chaperones, and metal transporters. The transcriptome were analyzed further with Gene Ontology (GO) and Cluster of Orthologous Groups (COGs) of proteins and showed diverse biological functions and metabolic pathways under Hg stress.

Construction of Artificial Biosynthetic Pathways for Resveratrol Glucoside Derivatives

  • Choi, Oksik;Lee, Jae Kyoung;Kang, Sun-Young;Pandey, Ramesh Prasad;Sohng, Jae-Kyung;Ahn, Jong Seog;Hong, Young-Soo
    • Journal of Microbiology and Biotechnology
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    • v.24 no.5
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    • pp.614-618
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    • 2014
  • Resveratrol, which is a polyphenolic antioxidant, is dose-dependent when used to provide health benefits, to enhance stress resistance, and to extend lifespans. However, even though resveratrol has therapeutic benefits, its clinical therapeutic effect is limited owing to its low oral bioavailability. An Escherichia coli system was developed that contains an artificial biosynthetic pathway that produces resveratrol glucoside derivatives, such as resveratrol-3-Oglucoside (piceid) and resveratrol-4'-O-glucoside (resveratroloside), from simple carbon sources. This artificial biosynthetic pathway contains a glycosyltransferase addition (YjiC from Bacillus) with resveratrol biosynthetic genes. The produced glucoside compounds were verified through the presence of a product peak(s) and also through LC/MS analyses. The strategy used in this research demonstrates the first harnessing of E. coli for de novo synthesis of resveratrol glucoside derivatives from a simple sugar medium.

Characterization of an Apple Polygalacturonase-Inhibiting Protein (PGIP) That Specifically Inhibits an Endopolygalacturonase (PG) Purified from Apple Fruits Infected with Botryosphaeria dothidea

  • Lee Dong-Hoon;Bae Han-Hong;Kang In-Kyu;Byun Jae-Kyun;Kang Sang-Gu
    • Journal of Microbiology and Biotechnology
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    • v.16 no.8
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    • pp.1192-1200
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    • 2006
  • An apple polygalacturonase-inhibiting protein (PGIP), which specifically inhibits endopolygalacturonase (PG, EC 3.2.1.15) from Botryosphaeria dothidea, was purified from Botryosphaeria dothidea-infected apple (Malus domestica cv. Fuji) fruits. The purified apple PGIP had a molecular mass of 40 kDa. The N-terminal amino acid sequence of the purified protein showed high homologies to those of PGIP from pear (100%), tomato (70%), and bean (65%). We also purified polygalacturonase (PG) from B. dothidea. The PG hydrolyzes pectic components of plant cell walls. When the extracted apple pectic cell wall material was treated with purified apple PGIP and B. dothidea PG, the amount of uronic acid released was lower than that treated with B. dothidea PG alone. This result demonstrates that PGIP functions specifically by inhibiting cell wall maceration of B. dothidea PG Furthermore, we characterized the de novo function of the PGIP against PG on the solubilization and depolymerization of polyuronides from cell wall of apple fruits inoculated with B. dothidea. This result demonstrated that the PGIP of plants exhibits one of the direct defense mechanisms against pathogen attack by inhibiting PGs that are released from pathogens for hydrolysis of cell wall components of plants.

An Unusual Bioconjugate of Glycerol and Poly(${\gamma}$-Glutamic Acid) Produced by Bacillus subtilis C1

  • SHIH ING-LUNG;WU JANE-YII;WU PEI-JEN;SHEN MING-HAU
    • Journal of Microbiology and Biotechnology
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    • v.15 no.5
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    • pp.919-923
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    • 2005
  • A bacterium capable of poly(${\gamma}$-glutamic acid) production was isolated from nonpasteurized soy sauce. It was judged to be a variety of Bacillus subtilis and designated as B. subtilis C1. B. subtilis C1 produced ${\gamma}$-PGA in the absence of exogenous glutamic acid; therefore, it is a de novo PGA­producing bacterium. The product produced by B. subtilis C1 was characterized by amino acid analysis to be composed of solely glutamic acid. However, the $H^1-NMR$ spectra showed chemical shifts of glycerol protons in addition to those of authentic ${\gamma}$-PGA, indicating that the product is in fact a bioconjugate of ${\gamma}$-PGA. The finding is unique, because the microbial production of ${\gamma}$-PGA bioconjugate has never been reported before. The molecular mass of the product was over 10,000 kDa as determined by GPC, and $97\%$ of the product was D-glutamate, indicating that L-glutamate was converted to its D-form counterpart by B. subtilis C1.

Genome Sequencing and Genome-Wide Identification of Carbohydrate-Active Enzymes (CAZymes) in the White Rot Fungus Flammulina fennae

  • Lee, Chang-Soo;Kong, Won-Sik;Park, Young-Jin
    • Microbiology and Biotechnology Letters
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    • v.46 no.3
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    • pp.300-312
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    • 2018
  • Whole-genome sequencing of the wood-rotting fungus, Flammulina fennae, was carried out to identify carbohydrate-active enzymes (CAZymes). De novo genome assembly (31 kmer) of short reads by next-generation sequencing revealed a total genome length of 32,423,623 base pairs (39% GC). A total of 11,591 gene models in the assembled genome sequence of F. fennae were predicted by ab initio gene prediction using the AUGUSTUS tool. In a genome-wide comparison, 6,715 orthologous groups shared at least one gene with F. fennae and 10,667 (92%) of 11,591 genes for F. fennae proteins had orthologs among the Dikarya. Additionally, F. fennae contained 23 species-specific genes, of which 16 were paralogous. CAZyme identification and annotation revealed 513 CAZymes, including 82 auxiliary activities, 220 glycoside hydrolases, 85 glycosyltransferases, 20 polysaccharide lyases, 57 carbohydrate esterases, and 45 carbohydrate binding-modules in the F. fennae genome. The genome information of F. fennae increases the understanding of this basidiomycete fungus. CAZyme gene information will be useful for detailed studies of lignocellulosic biomass degradation for biotechnological and industrial applications.

Sequence to Structure Approach of Estrogen Receptor Alpha and Ligand Interactions

  • Chamkasem, Aekkapot;Toniti, Waraphan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.6
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    • pp.2161-2166
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    • 2015
  • Estrogen receptors (ERs) are steroid receptors located in the cytoplasm and on the nuclear membrane. The sequence similarities of human $ER{\alpha}$, mouse $ER{\alpha}$, rat $ER{\alpha}$, dog $ER{\alpha}$, and cat $ER{\alpha}$ are above 90%, but structures of $ER{\alpha}$ may different among species. Estrogen can be agonist and antagonist depending on its target organs. This hormone play roles in several diseases including breast cancer. There are variety of the relative binding affinity (RBA) of ER and estrogen species in comparison to $17{\beta}-estradiol$ (E2), which is a natural ligand of both $ER{\alpha}$ and $ER{\beta}$. The RBA of the estrogen species are as following: diethyl stilbestrol (DES) > hexestrol > dienestrol > $17{\beta}-estradiol$ (E2) > 17- estradiol > moxestrol > estriol (E3) >4-OH estradiol > estrone-3-sulfate. Estrogen mimetic drugs, selective estrogen receptor modulators (SERMs), have been used as hormonal therapy for ER positive breast cancer and postmenopausal osteoporosis. In the postgenomic era, in silico models have become effective tools for modern drug discovery. These provide three dimensional structures of many transmembrane receptors and enzymes, which are important targets of de novo drug development. The estimated inhibition constants (Ki) from computational model have been used as a screening procedure before in vitro and in vivo studies.

Molecular Cloning and Characterization of Expression Patterns of a Plastid ω-3 Fatty Acid Desaturase cDNA from Perilla frutescens

  • Lee, Seong-Kon;Kim, Kyung-Hwan;Kwon, Moo-Sik;Hwang, Young-Soo
    • Journal of Applied Biological Chemistry
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    • v.44 no.1
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    • pp.6-11
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    • 2001
  • An ${\omega}-3$ fatty acid desaturase gene which is involved in de novo synthesis of -Iinolenate was isolated from cDNA library of Perilla frutescens. A cDNA library was constructed with mRNA extracted from perilla seeds of 12 DAF. The cDNA clone consisting of 1317-bp open reading frame encoding 438 amino acids with a relative MW of 50kDa, was isolated and showed 65-83% similarities to other known genes. This cDNA is deduced to encode a plastidal ${\omega}-3$ fatty acid desaturase based on the fact that it has higher homology to plastidal ones than to microsomal ones and its N-terminal sequence shares several characteristics of transit peptides of chloroplast proteins. Southern blot analysis of genomic DNA indicated that more than one gene or alleles for ${\omega}-3$ fatty acid desaturase are present in the genome of perilla. Northern blot analysis showed that the ${\omega}-3$ fatty acid desaturase gene is mainly revealed in early developing seeds and has different expression patterns depending on tissue types compared to the microsomal ones.

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Genetic Syndromes Associated with Craniosynostosis

  • Ko, Jung Min
    • Journal of Korean Neurosurgical Society
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    • v.59 no.3
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    • pp.187-191
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    • 2016
  • Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures. It leads not only to secondary distortion of skull shape but to various complications including neurologic, ophthalmic and respiratory dysfunction. Craniosynostosis is very heterogeneous in terms of its causes, presentation, and management. Both environmental factors and genetic factors are associated with development of craniosynostosis. Nonsyndromic craniosynostosis accounts for more than 70% of all cases. Syndromic craniosynostosis with a certain genetic cause is more likely to involve multiple sutures or bilateral coronal sutures. FGFR2, FGFR3, FGFR1, TWIST1 and EFNB1 genes are major causative genes of genetic syndromes associated with craniosynostosis. Although most of syndromic craniosynostosis show autosomal dominant inheritance, approximately half of patients are de novo cases. Apert syndrome, Pfeiffer syndrome, Crouzon syndrome, and Antley-Bixler syndrome are related to mutations in FGFR family (especially in FGFR2), and mutations in FGFRs can be overlapped between different syndromes. Saethre-Chotzen syndrome, Muenke syndrome, and craniofrontonasal syndrome are representative disorders showing isolated coronal suture involvement. Compared to the other types of craniosynostosis, single gene mutations can be more frequently detected, in one-third of coronal synostosis patients. Molecular diagnosis can be helpful to provide adequate genetic counseling and guidance for patients with syndromic craniosynostosis.

PRIMARY INTRAOSSEOUS CARCINOMA;REPORT OF 2 CASES (악골에서 발생한 원발성 상피암;2례 보고)

  • Park, So-Yeon;Kim, Jin;Lee, Choong-Kook;Park, Hyung-Rae;Kim, Il-Kyu
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.12 no.2
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    • pp.62-68
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    • 1990
  • Intraosseous carcinoma of the jaw may arise as metastatic lesions most commonly from breast, lung, kindney and thyroid and also primarily occur from ameloblastoma or odontogenic cyst. Rarely primary intraosseous carcinoma could be originated from the epithelium involved in odontogenesis. According to WHO's classification, primary intraosseous carcinoma is defined as squamous cell carcinoma, occured in the Jaw without connection to the oral mucosa. However, Elzay defined primary intraosseous carcinoma as malignant epithelial tumor related to the odontogenic apparatus, including carcinoma ex-odontogenic cyst, carcinoma ex-ameloblastoma and carcinoma de novo. We experienced 2 cases of intraosseous carcinoma of the jaw. The first case, a 59-year-old man, showed a ill-defined mass on the left maxilla, measuring $8{\times}10cm$ in size. He received radical hemimaxillectomy and was diagnosed as ameloblastic carcinoma. The second case obtained from a 79-year-old woman showed a ill-defined $6{\times}8cm$ sized mass on the left mandibular body area. The mass was surgically removed by partial mandibulaectomy, which was diagnosed as the primary intraosseous carcinoma, probably odontogenic origin.

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