• 제목/요약/키워드: Small molecules

검색결과 675건 처리시간 0.03초

Site-specific Mutagenesis에 의한 PRD1 DNA Polymerase의 활성부위 결정 (Determination of Active Site in PRD1 DNA Polymerase by Site-specific Mutagenesis)

  • 황정원;정구홍
    • 미생물학회지
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    • 제29권4호
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    • pp.209-214
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    • 1991
  • The PRD1 DNA polymerase is a small multi-functional enzyme containing conserved amino acid sequences shared by family B DNA polymerases. Thus the PRD1 DNA polymerase provides an useful model system with which to study structure-functional relationships of DNA polymerase molecules. In order to investigate the functional and structural roles of the highly conserved amino acid sequences, we have introduced three mutations into a conserved amino acid of the PRD1 DNA polymerase. Genetic complememtation study indicated that each mutation inactivated DNA polymerase catalytic activity.

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Voltammetric Behaviors of Chemically Modified Electrodes Based on Zirconium Phosphonate Film

  • 홍훈기
    • Bulletin of the Korean Chemical Society
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    • 제16권9호
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    • pp.886-891
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    • 1995
  • Electroactive monolayers based on zirconium(Ⅳ) phosphonate film were prepared on gold and tin oxide electrodes by sequential layer-by-layer depostion technique. High transfer coefficient values and surface coverages of surface bound redox molecules were obtained from the electrochemical measurements of heterogeneous electron transfer rates for monolayer modified electrodes. 1,10-Decanediylbis(phosphonic acid) (DBPA) monolayer as insulating barrier was effective in blocking electron transfer. However, these film modified oxide electrode shows voltammetric behavior of diffusion/permeation process taking place at very small exposed area of modified electrode through channels due to structural defects within film when a very fast redox couple such as Ru(NH3)63+ is hired.

Discovery of Novel RNA Targets Using Chemical Genomics

  • Yu, Jae-Hoon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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    • pp.93-93
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    • 2003
  • RNA plays an important role in numerous biological processes but little is known about the interactions between small organic molecules and RNA. Our previous work has shown that the heterodimeric compound designed by conjugation with neomycin and loop-specific chemical bind to the stem-loop structured RNA motifs. In the present study, heterodimer was used, in a reverse way, as a probe to identify structured RNA motifs. (omitted)

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Identification of new ligands for RNA pseudoknot by structure-based screening of chemical database

  • Park, So-Jung;Jeong, Seung-Hyun;Kim, Yang-Gyun;Park, Hyun-Ju
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.254.2-254.2
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    • 2003
  • For many viruses, -1 ribosomal frameshifting regulate protein synthesis using an RNA pseudoknot. The integrity of pseudoknot stability and structure is the important feature for efficient frameshifting. Thus, small molecules interacting with viral RNA pseudoknots would be potential antiviral agents targeting\ulcorner frameshifting system in viruses. X-ray structure of RNA pseudoknot complexed with biotin has been reported, in which biotin is bound at the interface between the pseudoknot's stacked helices. (omitted)

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Virtual Screening, Docking and DFT Study of PRMT5

  • Subathra, S
    • 통합자연과학논문집
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    • 제15권4호
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    • pp.187-194
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    • 2022
  • Protein Arginine Methyltransferase 5 (PRMT5), a significant member of the PRMT family, is a promising anticancer target. In this study, novel small compounds that act against the PRMT5 target are found by combining virtual screening with ChEMBL database medicines and Density Functional Theory. The ChEMBL database compounds were screened to retrieve the hit molecules, which further subjected for DFT analysis. Finally we have evaluated that ChEMBL- approved drugs such as Lifitegrast, Abiraterone acetate and Solifenacin may be potential inhibitors for PRMT5.

High Efficiency AMOLED Using Hybrid of Small Molecule and Polymer Materials Patterned by Laser Transfer

  • Chin, Byung-Doo;Suh, Min-Chul;Kim, Mu-Hyun;Kang, Tae-Min;Yang, Nam-Choul;Song, Myung-Won;Lee, Seong-Taek;Kwon, Jang-Hyuk;Chung, Ho-Kyoon;Wolk, Martin B.;Bellmann, Erika;Baetzold, John P.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.163-166
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    • 2003
  • Laser-Induced Thermal Imaging (LITI) is a laser addressed patterning process and has unique advantages, such as high-resolution patterning with over-all position accuracy of the imaged stripes within 2.5 micrometer and scalability to large-size mother glass. This accuracy is accomplished using real-time error correction and a high -resolution stage control system that includes laser interferometers. Here the new concept of mixed hybrid system which complement the advantages of small molecular and polymeric materials for use as an OLED; our system can realize the easy processing of polymers and high luminance efficiency of recently developed small molecules. LITI process enables to pattern the stripes with excellent thickness uniformity and multi-stacking of various functional layers without using any type of fine metal shadow mask. In this study, we report a full-color hybrid OLED using the multi-layered structure of small molecular/polymeric species.

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Density Functional Theory Studies of Oxygen Affinity of Small Au Nanoparticles

  • Ha, Hyunwoo;Shin, Kihyun;Kim, Hyun You
    • 한국재료학회지
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    • 제27권4호
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    • pp.229-235
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    • 2017
  • Through density functional theory calculations, to provide insight into the origins of the catalytic activity of Au nanoparticles (NPs) toward oxidation reactions, we have scrutinized the oxygen adsorption chemistry of 9 types of small unsupported Au NPs of around 1 nm in size (Au13, Au19, Au20, Au25, Au38, and Au55) looking at several factors (size, shape, and coordination number). We found that these NPs, except for the icosahedral Au13, do not strongly bind to $O_2$ molecules. Energetically most feasible $O_2$ adsorption that potentially provides high CO oxidation activity is observed in the icosahedral Au13, our smallest Au NP. In spite of the chemical inertness of bulk Au, the structural fluxionality of such very small Au NP enables strong $O_2$ adsorption. Our results can support recent experimental findings that the exceptional catalytic activity of Au NPs comes from very small Au species consisting of around 10 atoms each.

Segmented Filamentous Bacteria Induce Divergent Populations of Antigen-Specific CD4 T Cells in the Small Intestine

  • Yi, Jaeu;Jung, Jisun;Han, Daehee;Surh, Charles D.;Lee, You Jeong
    • Molecules and Cells
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    • 제42권3호
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    • pp.228-236
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    • 2019
  • CD4 T cells differentiate into $ROR{\gamma}t/IL$-17A-expressing cells in the small intestine following colonization by segmented filamentous bacteria (SFB). However, it remains unclear whether SFB-specific CD4 T cells can differentiate directly from naïve precursors, and whether their effector differentiation is solely directed towards the Th17 lineage. In this study, we used adoptive T cell transfer experiments and showed that naïve CD4 T cells can migrate to the small intestinal lamina propria (sLP) and differentiate into effector T cells that synthesize IL-17A in response to SFB colonization. Using single cell RT-PCR analysis, we showed that the progenies of SFB responding T cells are not uniform but composed of transcriptionally divergent populations including Th1, Th17 and follicular helper T cells. We further confirmed this finding using in vitro culture of SFB specific intestinal CD4 T cells in the presence of cognate antigens, which also generated heterogeneous population with similar features. Collectively, these findings indicate that a single species of intestinal bacteria can generate a divergent population of antigen-specific effector CD4 T cells, rather than it provides a cytokine milieu for the development of a particular effector T cell subset.

Morphological Characterization of small, dumpy, and long Phenotypes in Caenorhabditis elegans

  • Cho, Joshua Young;Choi, Tae-Woo;Kim, Seung Hyun;Ahnn, Joohong;Lee, Sun-Kyung
    • Molecules and Cells
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    • 제44권3호
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    • pp.160-167
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    • 2021
  • The determinant factors of an organism's size during animal development have been explored from various angles but remain partially understood. In Caenorhabditis elegans, many genes affecting cuticle structure, cell growth, and proliferation have been identified to regulate the worm's overall morphology, including body size. While various mutations in those genes directly result in changes in the morphological phenotypes, there is still a need for established, clear, and distinct standards to determine the apparent abnormality in a worm's size and shape. In this study, we measured the body length, body width, terminal bulb length, and head size of mutant worms with reported Dumpy (Dpy), Small (Sma) or Long (Lon) phenotypes by plotting and comparing their respective ratios of various parameters. These results show that the Sma phenotypes are proportionally smaller overall with mild stoutness, and Dpy phenotypes are significantly stouter and have disproportionally small head size. This study provides a standard platform for determining morphological phenotypes designating and annotating mutants that exhibit body shape variations, defining the morphological phenotype of previously unexamined mutants.

Streptochlorin, a Marine Natural Product, Inhibits $NF-{\kappa}B$ Activation and Suppresses Angiogenesis In Vitro

  • Choi, In-Kwon;Shin, Hee-Jae;Lee, Hyi-Seung;Kwon, Ho-Jeong
    • Journal of Microbiology and Biotechnology
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    • 제17권8호
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    • pp.1338-1343
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    • 2007
  • Angiogenesis is an essential step in tumor progress and metastasis. Accordingly, small molecules that inhibit angiogenesis would appear to be a promising way to cure angiogenesis-related diseases, including cancer. In the present study, we report that streptochlorin, a small molecule from marine actinomycete, exhibits a potent antiangiogenic activity. The compound potently inhibited endothelial cell invasion and tube formation stimulated with vascular endothelial cell growth factor (VEGF) at low micromolar concentrations where it showed no cytotoxicity to the cells. In addition, streptochlorin inhibited TNF-${\alpha}$-induced $NF-{\kappa}B$ activation in the newly developed cell-based reporter gene assay. These data demonstrate that streptochlorin is a new inhibitor of $NF-{\kappa}B$ activation and can be a basis for the development of novel anti-angiogenic agents.