• Title/Summary/Keyword: molecular assembly

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A Study on the Negative Differential Resistance Properties of Self-Assembly Organic Thin Film with Nitro Group (니트로기를 가진 자기조립된 유기 초박막의 부성미분저항 특성에 관한 연구)

  • Kim, Seung-Un;Son, Jung-Ho;Kim, Byoung-Sang;Shin, Hoon-Kyu;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.811-813
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    • 2003
  • We investigated the electrical properties of self-assembled (4,4'-Di(ethynylphenyl)-2'-nitro-1-thioacetylbenzene), which has been well known as a conducting molecule having possible application to molecular level negative differential resistance(NDR)[1]. Generally, the phenomenon of NDR can be characterized by the decreasing current with the increasing voltage[2]. To deposit the SAM layer onto gold electrode, we transfer the prefabricated nanopores into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured the voltage-current properties and confirmed the negative differential resistance properties of self-assembled organic thin film and measured, using Scanning Tunneling Microscopy(STM).

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Gene Therapy for Bovine Fatty Liver : Possibilities and Problems - A Review

  • Chen, Daiwen;Grummer, Ric
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.9
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    • pp.1331-1341
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    • 2001
  • Dairy cows are prone to fatty liver during the time of periparturient. Despite of the extensive studies, etiology and solutions for fatty liver are still not well known.The liver synthesizes triglycerides (TG) using precursors from bloodstream and secretes TG in form of very low density lipoprotein (VLDL) into bloodstream for the utilization by peripheral tissues. When the amount of TG synthesis exceeds the amount of secretion in VLDL-TG, TG accumulation within the liver occurs. Hepatic VLDL assembly and secretion involve multi-biochemical events.The availabilities of apolipoprotein B (apoB), E (apoE), microsomal triglyceride transfer protein (MTP) and soluble low density lipoprotein (LDL) receptor are now believed to be some of the main regulators for hepatic VLDL assembly and secretion. Studies in transgenic animals show that overexpression of these proteins stimulates VLDL production and secretion, which provides a possibility for alleviating bovine fatty liver by gene therapy. However, many problems remain to be solved to attain this goal. This review focuses on the molecular mechanisms of hepatic VLDL assembly and secretion, and the possibilities and problems of applying the knowledges to solve bovine fatty liver by gene therapy.

The Utilization of Oleogels for Cosmetics (화장품에서의 올레오겔 이용)

  • Cho, Wan-Goo
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.16-34
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    • 2013
  • Oleogels may be defined as lipophilic liquid and solid mixtures. The solid lipid materials (oleogelators) with less than 10 wt.% can entrap bulk liquid oil by ways of the formation of network of oleogelators in the bulk oil. The oelogelators can be grouped into two: self-assembly system and crystal particles system. This article reviewed recent work on the formation of oleogels using various types of oleogelators. The fundamental aspects of the formation of lipid network are discussed with a special emphasis on crystal particle based oleogels. The potential applications of oleogels for cosmetics are also described.

Acceleration of X-chromosome gene order evolution in the cattle lineage

  • Park, Woncheoul;Oh, Hee-Seok;Kim, Heebal
    • BMB Reports
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    • v.46 no.6
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    • pp.310-315
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    • 2013
  • The gene order on the X chromosome of eutherians is generally highly conserved, although an increase in the rate of rearrangement has been reported in the rodent lineage. Conservation of the X chromosome is thought to be caused by selection related to maintenance of dosage compensation. However, we herein reveal that the cattle (Btau4.0) lineage has experienced a strong increase in the rate of X-chromosome rearrangement, much stronger than that previously reported for rodents. We also show that this increase is not matched by a similar increase on the autosomes and cannot be explained by assembly errors. Furthermore, we compared the difference in two cattle genome assemblies: Btau4.0 and Btau6.0 (Bos taurus UMD3.1). The results showed a discrepancy between Btau4.0 and Btau6.0 cattle assembly version data, and we believe that Btau6.0 cattle assembly version data are not more reliable than Btau4.0.

Production of Nucleocapsid Protein of Newcastle Disease Virus in Escherichia coli and its Assembly into Ring-and Nucleocapsid-like Particles

  • Kho, Chiew-Ling;Tan, Wen-Siang;Khatijah Yusoff
    • Journal of Microbiology
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    • v.39 no.4
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    • pp.293-299
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    • 2001
  • The nucleocapsid(NP) protein of Newcastle disease virus (NDV) and its derivative (NP$\sub$cfus)containing the myc region and six histidine residues fused to its C-terminus were pcpressed aboundantly in Escherichia coli. The proteins were purified by sucrose gradient centrifugation. Both the NP and NP$\sub$cfus/ proteins self-assem- bled into ring-like particles stacked together to from nucleocapsid-like structure which are heterogeneous in length with a diameter of 20${\pm}$2 nm and central holow of 5${\pm}$1 nm. Only a very small amount of the monomers in the particles was linked by inter-molecular disulfide bonds. Fusion of the C-terminal end to 29 amino acids inclusive of the myc epitope and His tag did not impair ring assembly buy inhibited the formation of the long herringbone structures. Immunogold lableing of the particles with the anti-myc antibody showed that the C-terminus of the NP$\sub$cfus/ protein is exposed on the surface of these ring-like particles.

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TSG101 Physically Interacts with Linear Ubiquitin Chain Assembly Complex (LUBAC) and Upregulates the TNFα-Induced NF-κB Activation

  • Eunju Kim;Hyunchu Cho;Gaeul Lee;Heawon Baek;In Young Lee;Eui-Ju Choi
    • Molecules and Cells
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    • v.46 no.7
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    • pp.430-440
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    • 2023
  • Linear ubiquitin chain assembly complex (LUBAC) is a ubiquitin E3 ligase complex composed of HOIP, HOIL-1L, and SHARPIN that catalyzes the formation of linear/M1-linked ubiquitin chain. It has been shown to play a pivotal role in the nuclear factor (NF)-κB signaling induced by proinflammatory stimuli. Here, we found that tumor susceptibility gene (TSG101) physically interacts with HOIP, a catalytic component of LUBAC, and potentiates LUBAC activity. Depletion of TSG101 expression by RNA interference decreased TNFα-induced linear ubiquitination and the formation of TNFα receptor 1 signaling complex (TNF-RSC). Furthermore, TSG101 facilitated the TNFα-induced stimulation of the NF-κB pathway. Thus, we suggest that TSG101 functions as a positive modulator of HOIP that mediates TNFα-induced NF-κB signaling pathway.

Identification of small molecules that inhibit the histone chaperone Asf1 and its chromatin function

  • Seol, Ja-Hwan;Song, Tae-Yang;Oh, Se Eun;Jo, Chanhee;Choi, Ahreum;Kim, Byungho;Park, Jinyoung;Hong, Suji;Song, Ilrang;Jung, Kwan Young;Yang, Jae-Hyun;Park, Hwangseo;Ahn, Jin-Hyun;Han, Jeung-Whan;Cho, Eun-Jung
    • BMB Reports
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    • v.48 no.12
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    • pp.685-690
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    • 2015
  • The eukaryotic genome is packed into chromatin, which is important for the genomic integrity and gene regulation. Chromatin structures are maintained through assembly and disassembly of nucleosomes catalyzed by histone chaperones. Asf1 (anti-silencing function 1) is a highly conserved histone chaperone that mediates histone transfer on/off DNA and promotes histone H3 lysine 56 acetylation at globular core domain of histone H3. To elucidate the role of Asf1 in the modulation of chromatin structure, we screened and identified small molecules that inhibit Asf1 and H3K56 acetylation without affecting other histone modifications. These pyrimidine-2,4,6-trione derivative molecules inhibited the nucleosome assembly mediated by Asf1 in vitro, and reduced the H3K56 acetylation in HeLa cells. Furthermore, production of HSV viral particles was reduced by these compounds. As Asf1 is implicated in genome integrity, cell proliferation, and cancer, current Asf1 inhibitor molecules may offer an opportunity for the therapeutic development for treatment of diseases.

Expression and Purification of Intact and Functional Soybean (Glycine max) Seed Ferritin Complex in Escherichia coli

  • Dong, Xiangbai;Tang, Bo;Li, Jie;Xu, Qian;Fang, Shentong;Hua, Zichun
    • Journal of Microbiology and Biotechnology
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    • v.18 no.2
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    • pp.299-307
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    • 2008
  • Soybean seed ferritin is essential for human iron supplementation and iron deficiency anemia prevention because it contains abundant bioavailable iron and is frequently consumed in the human diet. However, it is poorly understood in regards its several properties, such as iron mineralization, subunit assembly, and protein folding. To address these issues, we decided to prepare the soybean seed ferritin complex via a recombinant DNA approach. In this paper, we report a rapid and simple Escherichia coli expression system to produce the soybean seed ferritin complex. In this system, two subunits of soybean seed ferritin, H-2 and H-1, were encoded in a single plasmid, and optimal expression was achieved by additionally coexpressing a team of molecular chaperones, trigger factor and GroEL-GroES. The His-tagged ferritin complex was purified by $Ni^{2+}$ affinity chromatography, and an intact ferritin complex was obtained following His-tagged enterokinase (His-EK) digestion. The purified ferritin complex synthesized in E. coli demonstrated some reported features of its native counterpart from soybean seed, including an apparent molecular weight, multimeric assembly, and iron uptake activity. We believe that the strategy described in this paper may be of general utility in producing other recombinant plant ferritins built up from two types of subunits.

Peptide Domain Involved in the Interaction between Membrane Protein and Nucleocapsid Protein of SARS-associated Coronavirus

  • Fang, Xiaonan;Ye, Linbai;Timani, Khalid Amine;Li, Shanshan;Zen, Yingchun;Zhao, Meng;Zheng, Hong;Wu, Zhenghui
    • BMB Reports
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    • v.38 no.4
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    • pp.381-385
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    • 2005
  • Severe acute respiratory syndrome (SARS) is an emerging infectious disease associated with a novel coronavirus (CoV) that was identified and molecularly characterized in 2003. Previous studies on various coronaviruses indicate that protein-protein interactions amongst various coronavirus proteins are critical for viral assembly and morphogenesis. It is necessary to elucidate the molecular mechanism of SARS-CoV replication and rationalize the anti-SARS therapeutic intervention. In this study, we employed an in vitro GST pull-down assay to investigate the interaction between the membrane (M) and the nucleocapsid (N) proteins. Our results show that the interaction between the M and N proteins does take place in vitro. Moreover, we provide an evidence that 12 amino acids domain (194-205) in the M protein is responsible for binding to N protein. Our work will help shed light on the molecular mechanism of the virus assembly and provide valuable information pertaining to rationalization of future anti-viral strategies.

Transcriptome Analysis of the Barley-Rhynchosporium secalis Interaction

  • Al-Daoude, Antonious;Shoaib, Amina;Al-Shehadah, Eyad;Jawhar, Mohammad;Arabi, Mohammad Imad Eddin
    • The Plant Pathology Journal
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    • v.30 no.4
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    • pp.425-431
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    • 2014
  • Leaf scald caused by the infection of Rhynchosporium secalis, is a worldwide crop disease resulting in significant loss of barley yield. In this study, a systematic sequencing of expressed sequence tags (ESTs) was chosen to obtain a global picture of the assembly of genes involved in pathogenesis. To identify a large number of plant ESTs, which are induced at different time points, an amplified fragment length polymorphism (AFLP) display of complementary DNA (cDNA) was utilized. Transcriptional changes of 140 ESTs were observed, of which 19 have no previously described function. Functional annotation of the transcripts revealed a variety of infection-induced host genes encoding classical pathogenesis-related (PR) or genes that play a role in the signal transduction pathway. The expression analyses by a semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) revealed that Rar1 and Rpg4 are defense inducible genes, and were consistent with the cDNA-AFLP data in their expression patterns. Hence, the here presented transcriptomic approach provides novel global catalogue of genes not currently represented in the EST databases.