• Title/Summary/Keyword: Hydrolyses

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Effect of Enzymatic Hydrolysis of 7S Globulin, a Soybean Protein, on Its Allergenicity and Identification of its Allergenic Hydrolyzed Fragments Using SDS-PAGE

  • Keum, Eun-Hee;Lee, Sang-Il;Oh, Sang-Suk
    • Food Science and Biotechnology
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    • v.15 no.1
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    • pp.128-132
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    • 2006
  • This study was undertaken to investigate the effect of peptic and chymotryptic hydrolyses of 7S globulin, the major allergen of soybean protein, on its allergenicity, as measured by enzyme linked immunosorbent assay (ELISA), and to identify the allergenic hydrolyzed fragments of 7S globulin using SDS-PAGE. When 7S globulin was hydrolyzed by pepsin, the allergenicity was reduced by over 50%. However, the allergenicity of 7S globulin reduced by peptic hydrolysis was recovered in the sera from 5 out of 10 patients following sequential chymotryptic hydrolysis. Two fragments, with molecular weights 20-25 and 13-16 kDa, among the hydrolysate of 7S globulin by sequential pepsin and chymotrypsin showed reactivity with sera from 10 soybean-allergenic patients. As a result of the theoretical hydrolyses of ${\beta}$-conglycinin, which is a major protein of 7S globulin, it is suggested that the 20-25 kDa fragments were the fragments of the ${\alpha}$-subunit of ${\beta}$'-conglycinin and that the 10-16 kDa fragments were from the ${\alpha}$'-subunit.

cDNA cloning of a membrane-associated. magnesium-dependent 30kDa neutral sphingomyelinase

  • Jeon, Hyung-Jun;Jung, Sung-Yun;Kim, Dae-Kyong
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.328.1-328.1
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    • 2002
  • A major lipid-signaling pathway in mammalian cells implicated the activation of sphingomyelinase (SMase), which hydrolyses sphingomyeline to generate ceramide and phosphocholine. Sphingomyelinase is divided into many isoform groups dependent on optimal pH, and essential cation especially magnesium in their activation. Such as acidic sphingomyelinase, neutral sphingomyelinase and alkaline sphingomyelinase. Ceramide is known as a crucial second messenger in cell responses like cell proliferation. cell cycle arrest. cellular senescence, and apoptosis. (omitted)

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Chemical Reactions in Surfactant Solutions (II). Nucleophilic and Micellar Catalyses of Sodium 2-Alkylbenzimidazole-5-sulfonates on Hydrolyses of Carboxylic Esters in Aqueous and CTABr Solutions (계면활성제 용액속에서의 화학반응 (제 2 보). 카르복시산 에스테르의 가수 분해 반응에 미치는 2-알킬벤즈이미다졸-5-술포네이트의 친핵적 및 미셀효과)

  • Young Seuk Hong;Jeung Bae Kim;Hee Hyun Park;Dae Ryong Lee
    • Journal of the Korean Chemical Society
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    • v.33 no.1
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    • pp.97-105
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    • 1989
  • This study deals with micellar effects on hydrolyses of p-nitrophenyl carboxylic esters(p-NPCE) mediated by 2-alkylbenzimidazole(R-BI) and sodium 2-alkylbenzimidazole-5-sulfonate(R-BISO$_3$Na) in aqueous and CTABr solutions. The reactions mediated by R-BI and R-BISO$_3$Na in micellar solutions are obviously slower than those by benzimidazole(BI) and sodium benzimidazole-5-sulfonate(BISO$_3$Na) respectively, and the reaction rates were decreased with increase of lengths of alkyl groups. This prestents a striking contrast to the reactions in aqueous solutions without added CTABr, of which the reaction rates are on approximately same levels. It seems due to steric effect of alkyl groups for R-BI and R-BISO$_3$Na in the Stern layer of micelle, and it is supported by measured activation parameters(${\Delta}H^{\neq},\;{\Delta}G^{\neq}\;and\;{\Delta}S^{\neq}$) of the reactions in aqueous and micellar solutions. In addition to nucleophilic ability of benzimidazole(BI) moiety of R-BISO$_3$Na on the reactions, these compounds with long alkyl groups(nonyl to pentadecyl) which form a micelle of themselves increase the reaction rates due to their micellar catalyses in aqueous solutions, not including CTABr. We measured the isotope effects to elucidate the mechanism of hydrolyses of p-nitrophenyl carboxylic esters, and the relative first order rate constant($k'_{H_2O}/k'_{D_2O}$) are on range of 2.5∼3.2. This range is too high to conclude that the hydrolyses of p-NPA mediated by various R-BISO$_3$Na proceed by nucleophilic mechanism. In other words, the reactions are assumed to proceed in part by general basic one, as compared with the reaction catalyzed by imidazole(IM) in aqueous solution.

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Thermodynamic Analysis on the Hydrolysis Reaction of Vinylsulfonyl Reactive Dyes (VS계 반응염료 가수분해반응의 열역학적 해석)

  • Gwon, Hyeok-Seong;Jeon, Yeong-Sil;Nam, Seong-U;Kim, In-Hoe
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2008.04a
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    • pp.74-76
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    • 2008
  • The hydrolyses of ten VS dyes were examined at 40$^{\circ}C$, 50$^{\circ}C$, and 60$^{\circ}C$ and the kinetic parameters were estimated. The values of free energy, enthalpy and entropy of hydrolysis and reaction with cellulose for VS dyes were calculated. The linear relationship exist between the enthalpy and entropy. The structure and entropy of VS dyes gave a effect on the dimerization for VS reactive dyes. The VS dyes have small value of entropy were formed dimer. It was confirmed that no dimer form for m-substituted VS dyes. There were similarities among various reactions including homo- and mixed dimerization.

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Acid and Nucleophile Catalysed Hydrolyses of Benzenesulfinamides (벤젠술핀아미드의 가수분해반응에서 산 및 할라이드 이온의 촉매작용)

  • Lee, Jong-Pal;Cho, Young-Su
    • Journal of Life Science
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    • v.20 no.12
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    • pp.1906-1909
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    • 2010
  • Acid and halide ion catalyses for the hydrolysis of benzenesulfinamides were kinetically investigated. The rates of hydrolysis increased with increasing concentration of both acid and halide ions and also showed to speed up as the electron donating ability of the benzenesulfinyl moiety and the electron withdrawing ability in the leaving group increased. The reactivity of halide ions was in the order of $Br^-$ > $Cl^-$. The reaction mechanism may be accommodated by including a hypervalent intermediate and sulfonium cation.