• Title/Summary/Keyword: Biological screening

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Structural Characteristics of Expression Module of Unidentified Genes from Metagenome (메타게놈 유래 미규명 유전자의 발현에 관련된 특성분석)

  • Park, Seung-Hye;Jeong, Young-Su;Kim, Won-Ho;Kim, Geun-Joong;Hur, Byung-Ki
    • KSBB Journal
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    • v.21 no.2
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    • pp.144-150
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    • 2006
  • The exploitation of metagenome, the access to the natural extant of enormous potential resources, is the way for elucidating the functions of organism in environmental communities, for genomic analyses of uncultured microorganism, and also for the recovery of entirely novel natural products from microbial communities. The major breakthrough in metagenomics is opened by the construction of libraries with total DNAs directly isolated from environmental samples and screening of these libraries by activity and sequence-based approaches. Screening with activity-based approach is presumed as a plausible route for finding new catabolic genes under designed conditions without any prior sequence information. The main limitation of these approaches, however, is the very low positive hits in a single round of screening because transcription, translation and appropriate folding are not always possible in E. coli, a typical surrogate host. Thus, to obtain information about these obstacles, we studied the genetic organization of individual URF's(unidentified open reading frame from metagenome sequenced and deposited in GenBank), especially on the expression factors such as codon usage, promoter region and ribosome binding site(rbs), based on DNA sequence analyses using bioinformatics tools. And then we also investigated the above-mentioned properties for 4100 ORFs(Open Reading Frames) of E. coli K-12 generally used as a host cell for the screening of noble genes from metagenome. Finally, we analyzed the differences between the properties of URFs of metagenome and ORFs of E. coli. Information derived from these comparative metagenomic analyses can provide some specific features or environmental blueprint available to screen a novel biocatalyst efficiently.

Isolation and Functional Analysis of spy1 Responsible for Pristinamycin Yield in Streptomyces pristinaespiralis

  • Jin, Qingchao;Yin, Huali;Hong, Xiaowei;Jin, Zhihua
    • Journal of Microbiology and Biotechnology
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    • v.22 no.6
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    • pp.793-799
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    • 2012
  • A gene related to high pristinamycin yield in Streptomyces pristinaespiralis was selected by amplified fragment length polymorphism (AFLP) and its functions were investigated by gene disruption. First, a 561 bp polymorphic sequence was acquired by AFLP from high-yield recombinants compared with the S. pristinaespiralis ancestor ATCC25486, indicating that this approach is an effective means of screening for valuable genes responsible for antibiotic yield. Then, a 2,127 bp open reading frame of a gene designated spy1 that overlaps with the above fragment was identified and its structure and biological functions were investigated. In silico analysis of spy1 encoding a deduced 708-amino-acid-long serine/threonine protein kinase showed that it only contains a catalytic domain in the N-terminal region, which is different from some known homologs. Gene inactivation of chromosomal spy1 indicated that it plays a pleiotropic regulatory function in pristinamycin production, with a positive correlation to pristinamycin I biosynthesis and a negative correlation to pristinamycin II biosynthesis.

The Relationship among Sun-Screening Agent Use, Bone Health Promotion Behavior and Bone Mineral Density of Female College Students (여대생의 자외선 차단제 사용과 골 건강증진행위 및 골밀도와의 관계)

  • Hyun, Hye Jin;Kim, Joo Hyun;Ko, Ga Yeon;Park, Bock Soon;Choi, Eun Young;Ahn, Mi Hyang
    • Journal of Korean Biological Nursing Science
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    • v.15 no.4
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    • pp.202-209
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    • 2013
  • Purpose: The purpose of this study is to investigate relationships among sun-screening agents use, bone health promotion behavior, and bone mineral density. Methods: The participants of this study were 105 female college students. The data were collected using a questionnaire about sun-screening agent use and bone health promotion behavior. Bone mineral density was measured with Ultrasound Bone Densitometer/Osteo Pro Series. Data were analyzed with the SPSS/Win 18.0 program. Results: The mean Z-score in female college students was $-1.04{\pm}1.26$, and the T-score was $-1.16{\pm}1.22$, 21.39% of the participants have osteopenia. Bone mineral density showed a significant correlation with weight. Bone mineral density showed no significant correlation between sun-screening agent use, and bone health promotion behavior. There was a significant correlation between protection power of sun-screening agents and the protection by clothes. Conclusion: According to the results of this study, we need to develop an intervention program for bone health promotion of female college students.

Molecular Cloning and Characterization of Sesquiterpene Cyclase cDNAs from Pepper Plant Infected with Phytophthora capsici

  • Kim, Jong-Bum;Lee, Sung-Gon;Ha, Sun-Hwa;Lee, Myung-Chul;Ye, Wan-Hye;Lee, Jang-Yong;Lee, Shin-Woo;Kim, Jung-Bong;Cho, Kang-Jin;Hwang, Young-Soo
    • Journal of Applied Biological Chemistry
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    • v.44 no.2
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    • pp.59-64
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    • 2001
  • Pepper plants (Nogkwang, 60-day old) were inoculated with Phytophthora capsici to induce sesquiterpene cyclase associated with the biosynthesis of phytoalexin (capsidiol), a substance related to the defense against pathogens in plants. One day after inoculation, mRNA was isolated from the root, cDNA synthesized, and a library constructed in a ZAP express XR vector. The efficiency was $2{\times}10^6pfu/{\mu}g$. Sesquiterpene cyclase cDNA from Hyoscyamus muticus was labeled with $^{32}P$ and used as a probe for screening the cDNA library. After the third screening, 25 positive clones were selected. Through restrictive digestion and DNA gel-blot analysis, six different cyclase gene expressions were identified. PSC1B sequences of the six clones were determined, which were 1966 base pairs encoded 556 amino acids with an expected molecular weight of 63.8 kDa. Response against the pathogen was different between the resistant and susceptible peppers. After the infection of the pathogen, the expression of PSC genes continued in the resistant peppers while the plants were alive. The expression in the susceptible peppers lasted for only 4 days.

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Considering Cell-based Assays and Factors for Genome-wide High-content Functional Screening

  • Chung, Chul-Woong;Kim, In-Ki;Jung, Yong-Keun
    • Animal cells and systems
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    • v.13 no.2
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    • pp.97-103
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    • 2009
  • Recently, great advance is achieved in the field of genome-wide functional screening using cell-based assay. Here, we briefly introduce well-established and typical cell-based assays of GPCR and some parameters which should be considered for genome-wide functional screening. Because of characters and importance of GPCR as drug targets, several ways of assay systems were devised. Among them, high-content screening (HCS) that is based on the analysis of image by confocal microscope is becoming favorite choice. The advances in this technology have been driven exclusively by industry for their convenience. Now, it is turn for academy to define more detail signaling networks via HCS using cDNA or siRNA libraries at genome-wide level. By isolating novel signaling mediators using cDNA or siRNA library, and postulating them as new candidates for therapeutic target, more understanding about life science and more increased chances to develop therapeutics against human disease will be achieved.

Screening of novel alkaloid inhibitors for vascular endothelial growth factor in cancer cells: an integrated computational approach

  • Shahik, Shah Md.;Salauddin, Asma;Hossain, Md. Shakhawat;Noyon, Sajjad Hossain;Moin, Abu Tayab;Mizan, Shagufta;Raza, Md. Thosif
    • Genomics & Informatics
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    • v.19 no.1
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    • pp.6.1-6.10
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    • 2021
  • Vascular endothelial growth factor (VEGF) is expressed at elevated levels by most cancer cells, which can stimulate vascular endothelial cell growth, survival, proliferation as well as trigger angiogenesis modulated by VEGF and VEGFR (a tyrosine kinase receptor) signaling. The angiogenic effects of the VEGF family are thought to be primarily mediated through the interaction of VEGF with VEGFR-2. Targeting this signaling molecule and its receptor is a novel approach for blocking angiogenesis. In recent years virtual high throughput screening has emerged as a widely accepted powerful technique in the identification of novel and diverse leads. The high resolution X-ray structure of VEGF has paved the way to introduce new small molecular inhibitors by structure-based virtual screening. In this study using different alkaloid molecules as potential novel inhibitors of VEGF, we proposed three alkaloid candidates for inhibiting VEGF and VEGFR mediated angiogenesis. As these three alkaloid compounds exhibited high scoring functions, which also highlights their high binding ability, it is evident that these alkaloids can be taken to further drug development pipelines for use as novel lead compounds to design new and effective drugs against cancer.