• Title/Summary/Keyword: Heterogeneous Reaction

Search Result 260, Processing Time 0.024 seconds

Potential Role of Bacterial Infection in Autoimmune Diseases: A New Aspect of Molecular Mimicry

  • Alam, Jehan;Kim, Yong Chul;Choi, Youngnim
    • IMMUNE NETWORK
    • /
    • v.14 no.1
    • /
    • pp.7-13
    • /
    • 2014
  • Molecular mimicry is an attractive mechanism for triggering autoimmunity. In this review, we explore the potential role of evolutionary conserved bacterial proteins in the production of autoantibodies with focus on granulomatosis with polyangiitis (GPA) and rheumatoid arthritis (RA). Seven autoantigens characterized in GPA and RA were BLASTed against a bacterial protein database. Of the seven autoantigens, proteinase 3, type II collagen, binding immunoglobulin protein, glucose-6-phosphate isomerase, ${\alpha}$-enolase, and heterogeneous nuclear ribonuclear protein have well-conserved bacterial orthologs. Importantly, those bacterial orthologs are also found in human-associated bacteria. The wide distribution of the highly conserved stress proteins or enzymes among the members of the normal flora and common infectious microorganisms raises a new question on how cross-reactive autoantibodies are not produced during the immune response to these bacteria in most healthy people. Understanding the mechanisms that deselect auto-reactive B cell clones during the germinal center reaction to homologous foreign antigens may provide a novel strategy to treat autoimmune diseases.

Antigenicity Study of Recombinant Human Erythropoietin (천연형 사람 적혈구 조혈인자의 항원성시험)

  • Kang, Kyung-Koo;Cho, Hyeon;Baik, Nam-Gi;Kim, Won-Bae
    • Biomolecules & Therapeutics
    • /
    • v.6 no.1
    • /
    • pp.50-55
    • /
    • 1998
  • Antigenic potential of a recombinant human erythropoietin (rhEPO) produced by Dong-A charm. Co. Ltd. was examined by active systemic anaphylaxis (ASA) test in guinea pigs, mouse-rat passive cutaneous anaphylaxis (PCA) reaction and passive hemagglutination (PHA) test. In ASA test, rhEPO induced the signs of restlessness, rubbing or licking nose, sneezing and coughing in the animals immunized with rhEPO 1000 lU/kg alone or rhEPO 1000 lU/kg incorporated into Freund\\\\`s complete adjuvant. In the mouse-rat PCA test, only one of six sera from the animals immunized with rhEPO 1000 lUng incorporated into Alum showed positive result. In the PHA test, rhEPO revealed negative results in all of the rhEPO-immunized groups. From these results, rhEPO was considered to produce IgE in guinea pigs and mice, but not IgG and/or IsM in mice. The results of this study were similar to those of the other recombinant human erythropoietin and these positive results were thought to be caused due to the fact that rhEPO were heterogeneous proteins to guinea pigs and mice. Considering the fact that rhErO has an identical structure with indigenous human erythropoietin, rhEPO is not thought to cause immunological problems in clinical use.

  • PDF

Effect of the Presence of Soil on the Ferrous Catalyzed Sodium Persulfate Oxidation of Naphthalene (과황산나트륨과 제일철 촉매를 이용한 나프탈렌 산화 시 토양이 미치는 영향 평가)

  • Han, Dai-Sung;Yun, Yeo-Bog;Ko, Seok-Oh
    • Journal of Soil and Groundwater Environment
    • /
    • v.15 no.1
    • /
    • pp.29-38
    • /
    • 2010
  • Batch tests were carried out to examine the influence of the presence of soil and Fe(II) sorption capacity of soil on the ferrous catalyzed sodium persulfate oxidation for the destruction of organic pollutants in the application of in-situ chemical oxidation. Laboratory column tests were also conducted to investigate the transport of oxidant and catalyst in contaminated groundwater. Test results proved that Fe(II) was adsorbed on soil surface, and thus soil behaved as a heterogeneous catalyst, enhancing the naphthalene removal rate up to 50%. Column tests that were conducted with and without dissolved Fe(II) showed that naphthalene removal ratio were 24% and 25%, respectively. The removal efficiency was not enhanced with dissolved Fe(II), since the dissolved Fe(II) flew out of the column as the oxidant progressively injected into the column saturated with Fe(II). It indicates that the injected oxidant could not interact with dissolved Fe(II). But target organic pollutant was degraded in soil column system, implying that sulfate radical was produced by the reaction of dissolved persulfate with Fe(II) adsorbed on soil.

A Novel Endo-β-1,4-xylanase from Acanthophysium sp. KMF001, a Wood Rotting Fungus

  • Yoon, Sae-Min;Kim, Yeong-Suk;Kim, Young-Kyoon;Kim, Tae-Jong
    • Journal of the Korean Wood Science and Technology
    • /
    • v.46 no.6
    • /
    • pp.670-680
    • /
    • 2018
  • Acanthophysium sp. KMF001, a wood rotting fungus, produces a strong crude enzyme complex that efficiently produces simple sugars from wood. The transcriptomic analysis of Acanthophysium sp. KMF001 identified 14 genes for putative glycoside hydrolases. Among them, isotig01043 was expressed heterogeneously in Escherichia coli BL21(DE3), and the expressed protein exhibited an endo-${\beta}$-1,4-xylanase activity which showed the optimum reaction at pH 5.0 and $30^{\circ}C$. The enzyme kinetic values of $K_m$ and $V_{max}$ were 25.92 mg/ml and $0.628{\mu}mole/mg/ml$, respectively. The enzymatic characteristics of the expressed xylanase showed a typical fungal xylanase. However, the bioinformatics analysis suggested that the protein encoded by isotig01043 was a novel xylanase based on a low identity when it was compared with the closest protein in the NCBI database and a similar protein domain with GH16_fungal_Lam16A_glucanase, which had not been earlier suggested as a xylanase.

Development of a browser for signal transduction network to simulate biochemical reaction in a cell (생체내 반응 시뮬레이션을 위한 신호전달 네트워크 브라우저 개발)

  • Yu, Seok Jong;Lee, Sang Joo
    • Proceedings of the Korea Contents Association Conference
    • /
    • 2007.11a
    • /
    • pp.539-542
    • /
    • 2007
  • After introducing some experiment methods including immunoprecipitation and yeast two-hybrid screening, the pool of molecular interaction data is growing fast and databases are produced dramatically. But it is difficult to apply the information to molecular kinetic studies for understanding disease. In this paper, we developed a program that can browse and visualize interactions of cellular molecules using importing heterogeneous external data file. This program support 3D view to navigate and understand more easily and making a signal transduction model that user wants and simulating function to research the model. It was tested for signal transduction of chmotaxis in bacteria.

  • PDF

Preparation of Surface-anionized Poly(vinyl alcohol-co-methacrylic acid) Hydrogel Beads (표면에 음이온이 도입된 폴리(비닐 알코올-co-메타아크릴산) 하이드로젤 입자의 제조)

  • 윤주표;박연흠;이세근;박기홍;이철주
    • Polymer(Korea)
    • /
    • v.27 no.2
    • /
    • pp.159-166
    • /
    • 2003
  • For the purpose of obtaining surface-anionized poly(vinyl alcohol) (PVA) hydrogel beads, vinyl acetate(VAc) and methacrylic acid(MMA) were copolymerized by the suspension polymerization technique and followed by the saponification. It was confirmed by $^1$H-NMR that the copolymerized microspheres contained carboxylic acid groups in their surface. poly(VAc-co-MAA) microspheres were completely saponified in the heterogeneous system. The saponification reaction was laster than that of PVAc microspheres. We observed the swelling property of saponified PVA microspheres treated in the acidic solution and in the alkaline solution successively. Saponified microspheres shrank in acidic solution and swelled in alkaline solution respectively, which was reversible. from the result, saponified microspheres were highly water-absorbing hydrogel beads and were certified -COOH group at their surface by $^1$H-NMR and FT-IR.

Synthesis, Characterization and Catalytic Evaluation of Zinc Fluorides for Biodiesel Production

  • Indrayanah, Sus;Marsih, I Nyoman;Murwani, Irmina Kris
    • Journal of the Korean Chemical Society
    • /
    • v.62 no.1
    • /
    • pp.7-13
    • /
    • 2018
  • The potential of zinc fluorides with different molar ratios of Zn/F was applied as a solid catalyst in the simultaneous reaction of transesterification and esterification of crude palm oil (CPO) for biodiesel production. These materials were prepared by the fluorolytic sol-gel technique with different fluorine contents. The resulting samples were investigated using elemental analysis, XRD, FT-IR, TG/DTG, $N_2$ physisorption measurements and SEM. The results exhibited that the presence of fluorine strongly affected the catalytic activity in the biodiesel production. The catalysts with smaller fluorine contents (${\leq}1$) showed the best performance in all of the observed samples, yields from 92.94 to 89.95, 87.38 and 85.21% with increasing fluorine contents, respectively. The yield toward the formation of biodiesel depended on the phase and particle sizes of catalysts, but it was not influenced by surface area, pore size, and volume of the samples. The recovered catalyst showed a gradual decrease in activity over three cycles of same reactions.

Effect of Chitin Sources on Production of Chitinase and Chitosanase by Streptomyces griseus HUT 6037

  • Kim, Kwang;Ji, Hong-Seok
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.6 no.1
    • /
    • pp.18-24
    • /
    • 2001
  • The advantage of using Streptomyces griseus HUT 6037 in the production of chitinase or chitosanase is that the organism is capable of hydrolyzing amorphous or crystalline chitin and chitosan according to the type of the substrate used. We investigated the effects of the enzyme induction time and chitin sources, CM-chitosan and deacetylated chitosan (degree of deacetylation 75-99%), on production of chitosanase. We found that this strain accumulated chitosanase when cells were grown in the culture medium containing chitosanaceous substrates instead of chitinaceous substrates. The highest chitosanase activity was obtained at 4 dyas of cultivation with 99% deacetylated chitosan. The specific activities of chitinase and chitosanase were 0.91 and 1.33 U/mg protein at 3 and 5 days, respectively. From the study of the enzymatic digestibility of various degrees of deacetylated chitosan, it was found that (GlcN)$_3$, (GlcN)$_4$and (GlcN)(sub)5 were produced during the enzymatic hydrolysis reaction. The results of this study suggested that the sugar composition of (GlcN)$_3$was homogeneous and those of (GlcN)$_4$and (GlcN)(sub)5 were heterogeneous.

  • PDF

Solid Waste from Swine Wastewater as a Fuel Source for Heat Production

  • Park, Myung-Ho;Kumar, Sanjay;Ra, ChangSix
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.25 no.11
    • /
    • pp.1627-1633
    • /
    • 2012
  • This study was to evaluate the feasibility of recycling the solids separated from swine wastewater treatment process as a fuel source for heat production and to provide a data set on the gas emissions and combustion properties. Also, in this study, the heavy metals in ash content were analyzed for its possible use as a fertilizer. Proximate analysis of the solid recovered from the swine wastewater after flocculation with organic polymer showed high calorific (5,330.50 kcal/kg) and low moisture (15.38%) content, indicating that the solid separated from swine wastewater can be used as an alternative fuel source. CO and NOx emissions were found to increase with increasing temperature. Combustion efficiency of the solids was found to be stable (95 to 98%) with varied temperatures. Thermogravimetry (TG) and differential thermal analysis (DTA) showed five thermal effects (four exothermic and one endothermic), and these effects were distinguished in three stages, water evaporation, heterogeneous combustion of hydrocarbons and decomposition reaction. Based on the calorific value and combustion stability results, solid separated from swine manure can be used as an alternative source of fuel, however further research is still warranted regarding regulation of CO and NOx emissions. Furthermore, the heavy metal content in ash was below the legal limits required for its usage as fertilizer.

Numerical Studies on Combustion Characteristics of a Hybrid Catalytic Combustor (하이브리드 촉매 연소기의 연소특성에 관한 수치적 연구)

  • Hwang, Cheol-Hong;Jeong, Yeong-Sik;Lee, Chang-Eon
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.25 no.4
    • /
    • pp.583-592
    • /
    • 2001
  • The combustion characteristics of the hybrid catalytic(catalytic+thermal) combustor with a lean methane-air mixture on platinum catalyst were investigated numerically using a 2-D boundary layer model with detailed homogeneous and heterogeneous chemistries. for the more accurate calculations, the actual surface site density of monolith coated with platinum was decided by the comparison with experimental data. It was found that the homogeneous reactions in the monolith had little effect on the change of temperature profile, methane conversion rate and light off location. However, the radicals such as OH and CO were produced rapidly at exit by homogeneous reactions. The effect of operation conditions such as equivalence ratio, temperature, velocity, pressure and diameter of the monolith channel at the entrance were studied. In thermal combustor, the production of N$_2$O was more dominant than that of NO due to the relative importance of the reaction N$_2$+O(+M)→N$_2$O(+M). Finally the productions of CO and NOx by amount of methane addition were studied.