• Title/Summary/Keyword: Site-Specificity

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Current advances in adenovirus nanocomplexes: more specificity and less immunogenicity

  • Kang, Eun-Ah;Yun, Chae-Ok
    • BMB Reports
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    • v.43 no.12
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    • pp.781-788
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    • 2010
  • An often overlooked issue in the field of adenovirus (Ad)-mediated cancer gene therapy is its limited capacity for effective systemic delivery. Although primary tumors can be treated effectively with intralesional injection of conventional Ad vectors, systemic metastasis is difficult to cure. Systemic administration of conventional naked Ads leads to acute accumulation of Ad particles in the liver, induction of neutralizing antibody, short blood circulation half-life, non-specific biodistribution in undesired organs, and low selective accumulation in the target disease site. Versatile strategies involving the modification of viral surfaces with polymers and nanomaterials have been designed for the purpose of maximizing Ad anti-tumor activity and specificity by systemic administration. Integration of viral and non-viral nanomaterials will substantially advance both fields, creating new concepts in gene therapeutics. This review focuses on current advances in the development of smart Ad hybrid nanocomplexes based on various design-based strategies for optimal Ad systemic administration.

Kinetic Study on Dephosphorylation of Myelin Basic Protein by Some Protein Phosphates

  • 황인성;김진한;최명운
    • Bulletin of the Korean Chemical Society
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    • v.18 no.4
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    • pp.428-432
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    • 1997
  • The dephosphorylation specificity of protein phosphatase 2A (PP2A), calcineurin (PP2B) and protein phosphatase 2C (PP2C) were studied in vitro using myelin basic protein (MBP) as a model substrate which was fully phosphorylated at multiple sites by protein kinase C (PKC) or cyclic AMP-dependent protein kinase (PKA). In order to determine the site specificity of phosphates in myelin basic protein, the protein was digested with trypsin and the radioactive phosphopeptide fragments were isolated by high performance liquid chromatography (HPLC) on reversed-phase column. Subsequent analysis and/or sequential manual Edman degradation of the purified phosphopeptides revealed that Thr-65 and Ser-115 were most extensively phophorylated by PKA and Ser-55 by PKC. For the dephosphorylation kinetics, the phosphorylated MBP was treated with calcineurin or PP2C with various time intervals and the reaction was terminated by direct tryptic digest. Both Thr-65 and Ser-115 residues were dephosphorylated more rapidly than any other ones by phosphatases. However it can be differentiated further by first-order kinetics that the PP2B dephosphorylated both Thr-65 and Ser-115 with almost same manner, whereas PP2C dephosphorylated somewhat preferentially the Ser-115.

Diagnostic Accuracy of Urease and Polymerase Chain Reaction to Detect Helicobacter Species Infection in Dogs (개에서 Helicobacter균 감염을 검출하기 위한 urease 검사와 PCR 검사의 진단적 정확도)

  • Pak, Son-Il;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.18 no.4
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    • pp.329-333
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    • 2001
  • Evaluation on the diagnostic performances of urease test and polymerase chain reaction (PCR) for detection of Helicobacter species infection in dogs has rarely been performed in research with site-specific situations, although assessing diagnostic tests is an essential part prior to its practical use in a variety of clinical settings. The clinical value of a diagnostic test may be misjudged and comparisons between different tests may yield misleading conclusions when high within-patient correlations are present. We applied a conceptually simple statistical approach to estimate the sensitivity and specificity of urease test and PCR for detection of Helicobacter species infection in dogs. This approach assumes that responses from three different sampling sites within an animal are correlated where unit for statistical analysis is the site rather than the animal. The sensitivity and specificity of urease test was 0.74% (95% confidence interval, 0.64-0.84) and 0.87 (95% CI, 0.67-1.00), respectively. For PCR, the sensitivity was 0.95(95% CI, 0.89-1.00) and specificity 0.90 (95% CI, 0.70-1.00). Two tests were almost equally specific. Urease test, however, has a lower diagnostic accuracy and thus should only be used after careful validation in terms of sensitivity.

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Site-Specificity and Environment of Visual Art in the Postmodern Era (포스트모던시대 조형예술의 장소성과 환경)

  • Lee, Bong-Soon
    • Journal of Science of Art and Design
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    • v.13 no.1
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    • pp.39-60
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    • 2008
  • Nature/Landscape is surrounding space in which we make living. It is considerably comprehensive tenn. but on the other hand, the site can be existence, experience, and certain circumstance with boundaries. Based on these places, through contemporary art criticism, this study is to contemplate how art since 1960s, especially, site-specific art in three-dimensional space intervene in the environment. Artists of today put more value on the process and act of art making founded on the external, and they tend to create the characteristic of site or to indicate linguistic documentation. Moreover, a large-scale tendency of contemporary sculpture and 'occupation of specific site' seems to accede spatial conception from architecture. The core that recognizes these artworks is with body, that is to say, the space in which Self becomes the subject by changing the structure of the work while moving around it. In particular, 'Site-specific Art (in situ)' sometimes determines the form inward or outward It also relates directly on viewer's five senses by looking, hearing, and feeling, touching, and interacting. For example, in Richard Serra's , the viewer who moves around the work has the role to manipulate the movement of the work by perception. Works of In situ and works that planned for specific site suggest 'occupation of site' as of the function of the work These sites are ideal and special as well as being independent. Ultimately, it seems that the creative process of contemporary artists is to carry those intended form on the structure of perception. Furthermore, law of nature such as entropy, and acceptance of contingency helped organic structure of artwork become more abundant. For Robert Smithson, entropy suggests of reaching to a state of equilibriumin which everything is the same. This means that any core is justifiable and any rank is possible. Because the world without a core is a labyrinth of boundless exploration.

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A study on the Interactive relationship between the public space and the public art - Focused on the Works of Daniel Buren - (현대 공공 공간과 공공미술의 상호 작용에 관한 연구 - 다니엘 뷰렌의 작품을 중심으로 -)

  • Kim, Hyun-Jung
    • Korean Institute of Interior Design Journal
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    • v.16 no.2 s.61
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    • pp.147-154
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    • 2007
  • This study places a great emphasis on the approaches to the space environment we inhabit, which I hope will contribute to generating a number of creative possibilities. Looking into 'site-specificity' which is characteristic by public art in public space method based on Daniel Buren's works 'in situ', this study analyze the relationship between the public space and works of art as a perspective of public art. The characteristics of his 'in situ' works that intervened works exist as space consisting of serial factors not simply art-object, and they suggest 'site Is a work'. The case study of Daniel Buren's public art project represented the results, the site marketing and serves as a guideline for the future of true Art/Space experiments. This study verifies the need for the arts and the space to work together in order to develop more creative and conceptual approaches to innovation and presentation. This cooperation is the continuation of space design by other means.

The active site and substrate binding mode of 1-aminocyclopropane-1- carboxylate oxidase of Fuji apple (Malus domesticus L.) determined by site directed mutagenesis and comparative modeling studies

  • Ahrim Yoo;Seo, Young-Sam;Sung, Soon-Kee;Yang, Dae-Ryook;Kim, Woo-Tae-K;Lee, Weontae
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.70-70
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    • 2003
  • Active sites and substrate bindings of 1-aminoxyclopropane-1-carboxylate oxidase (MD-ACO1) catalyzing the oxidative conversion of ACC to ethylene have been determined based on site-directed mutagenesis and comparative modeling methods. Molecular modeling based on the crystal structure of Isopenicillin N synthase (IPNS) provided MD-ACO1 structure. MD-ACO1 protein folds into a compact jelly roll shape, consisting of 9 ${\alpha}$-helices, 10 ${\beta}$-strands and several long loops. The MD-ACO1/ACC/Fe(II)/Ascorbate complex conformation was determined from automated docking program, AUTODOCK. The MD-ACO1/Fell complex model was consistent with well known binding motif information (HIS177-ASP179-HIS234). The cosubstrate, ascorbate is placed between iron binding pocket and Arg244 of MD-ACO1 enzyme, supporting the critical role of Arg244 for generating reaction product. These findings are strongly supported by previous biochemical data as well as site-directed mutagenesis data. The structure of enzyme/substrate suggests the structural mechanism for the biochemical role as well as substrate specificity of MD-ACO1 enzyme.

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Site-directed Mutagenesis of Cysteine Residues in Phi-class Glutathione S-transferase F3 from Oryza sativa

  • Jo, Hyun-Joo;Lee, Ju-Won;Noh, Jin-Seok;Kong, Kwang-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4169-4172
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    • 2012
  • To elucidate the roles of cysteine residues in rice Phi-class GST F3, in this study, all three cysteine residues were replaced with alanine by site-directed mutagenesis in order to obtain mutants C22A, C73A and C77A. Three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Cys73 and Cys77 residues in OsGSTF3 with alanine did not affect the glutathione conjugation activities, showing non-essentiality of these residues. On the other hand, the substitution of Cys22 residue with alanine resulted in approximately a 60% loss of specific activity toward ethacrynic acid. Moreover, the ${K_m}^{CDNB}$ value of the mutant C22A was approximately 2.2 fold larger than that of the wild type. From these results, the evolutionally conserved cysteine 22 residue seems to participate rather in the structural stability of the active site in OsGSTF3 by stabilizing the electrophilic substrates-binding site's conformation than in the substrate binding directly.

Case of Geophysical Survey Guideline for Site Investigation of Spent Nuclear Fuel disposal: Focusing on airborne electromagnetic and seismic reflection survey (사용후핵연료 처분시설 부지조사를 위한 물리탐사 수행지침서 작성 사례 : 항공전자탐사와 탄성파 반사법탐사 중심으로)

  • NamYoung Kong;Hagsoo Kim;Yoonsup Moon;Manho Han
    • Geophysics and Geophysical Exploration
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    • v.27 no.1
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    • pp.69-83
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    • 2024
  • Considering importance and specificity, site investigations for deep geological disposal of Spent Nuclear Fuel require stringent quality control, unlike general geotechnical investigations for tunnels and bridges. In this study, we present a case of selecting geophysical survey method for individual site investigation stage and preparing geophysical survey guideline. The proposed geophysical survey guidelines include procedures, considerations, and quality control for exploration planning, data acquisition, data processing, and interpretation. They comprehensively summarize the contents of airborne electromagnetic survey and seismic reflection survey.

Recognition of DNA by IHF : Sequence Specifficity Mediated by Residues That Do Not Contact DNA

  • Read, Erik K.;Cho, Eun Hee;Gardner, Jeffrey F.
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 2001.06a
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    • pp.35-39
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    • 2001
  • The Integration Host factor (IHF) of Escherichia coli is a small, basic protein that is required for a variety of functions including site-specific recombination, transposition, gene regulation, plasmid replication, and DNA packaging. It ,is composed of two subunits that are encoded by the ihfA ($\alpha$-subunit) and ihjB ($\beta$-subunit) genes. IHF binding sites are composed of three elements called the WATCAR, TTG, and poly (dAT) elements. We have characterized IHF binding to the H site of bacteriophage λ. We have isolated suppressors that bind to altered H' sites using a challenge phage selection. Two different suppressors were isolated that changed the adjacent $\alpha$P64 and $\alpha$K65 residues. The suppressors recognized both the wild-type site and a site with a change in the WATCAR element. Three suppressors were isolated at $\beta$-E44. These suppressors bound the wild-type and a mutant site with a T:A to A:T change (H44A) in the middle of the TIR element. Site-directed mutagenesis was used to make several additional changes at $\beta$E44. The wild-type and $\beta$E44D mutant could not bind the wild-type site but were able to bind the H44A mutant site. Other mutants with neutral, polar, or a positive charge at $\beta$E44 were able to repress both the wild-type and H44A sites. Examination of the IHF crystal structure suggests that the ability of the wild-type and $\beta$E44D proteins to discriminate between the T:A and A:T basepairs is due to indirect interactions. The $\beta$-E44 residue does not contact the DNA directly. It imposes binding specificity indirectly by interactions with residues that contact the DNA. Details of the proposed interactions are discussed.

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Purification of Aldose Reductase and Decolorization of Dye by the Enzyme

  • Jang, Mi;Kim, Kyung-Soon
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.358-361
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    • 2009
  • Aldose reductase was purified to electrophoretic homogeneity from porcine liver. The purified enzyme was a monomer of 36 kDa. The enzyme was strongly inhibited by $Cu^{2+}\;and\;Mg^{2+}$ ions. Incubation of the enzyme with pyridoxal 5'-phosphate led to complete inhibition of enzymatic activity, suggesting that lysine residue is involved at or near the active site of the enzyme. The enzyme exhibited a broad substrate specificity. Furthermore, the enzyme was capable of decolorizing Alizarin, an anthraquinone dye.