• 제목/요약/키워드: enzyme reactivity

검색결과 129건 처리시간 0.025초

Allergenic potential and enzymatic resistance of buckwheat

  • Lee, Sujin;Han, Youngshin;Do, Jeong-Ryong;Oh, Sangsuk
    • Nutrition Research and Practice
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    • 제7권1호
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    • pp.3-8
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    • 2013
  • Buckwheat is known as a health food but is one of the major food allergens triggering potentially fatal anaphylaxis in Asia, especially in Japan and Korea. This study was conducted to investigate the characteristic of enzymatic resistance of buckwheat protein and allergenic potential. Enzymatic resistance of buckwheat protein was performed with in vitro digestibility test in simulated gastric fluid (SGF), pH 1.2, using pepsin and simulated intestinal fluid (SIF) using chymotrypsin. Reactivity of buckwheat proteins to human IgE was performed using six allergic patients sensitized to buckwheat. Buckwheat's IgE levels were measured using the Phadia UniCAP-system. Buckwheat protein, 16 kDa, still remained after 30 min treatment of pepsin on SDS-PAGE. Even though 16 kDa almost disappeared after 60 min treatment, two out of the six buckwheat patients' sera showed reactivity to hydrolysate after 60 min treatment, indicating that allergenicity still remained. In simulated intestinal fluid (SIF) using chymotrypsin, buckwheat protein, 24 kDa, showed resistance to hydrolysis with chymotrypsin on SDS-PAGE, and still had allergenicity based on the result of ELISA. Our results suggest that buckwheat proteins have strong resistance to enzyme degradation. This may be attributed in part to the allergenic potential of buckwheat. Further study should be continued regarding buckwheat allergy.

Development of Immunological Methods for Analysis of 5' -deoxy-5' -methylthioadenosine

  • Lee, Sung-Ho;Cho, Young-Dong
    • BMB Reports
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    • 제30권6호
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    • pp.403-409
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    • 1997
  • Studies were undertaken to develop a competitive radioimmunoassay (RIA) and indirect antigen capture enzyme-linked immunosorbent assay (ELISA) for the determination of 5'-deoxy-5'-methylthioadenosine (MTA), which is formed from decarboxylated S-adenosylmethionine by spermidine and spermine synthase. Specific antiserum against MTA was raised in rabbits by immunization with MTA-BSA which was prepared by coupling BSA to oxidized MTA with periodate. Since MTA is oxidized easily to the sulfoxide, the sulfhydryl reagent, DTT. was added to the immunogen. For RIA, immunocomplexes were separated from free MTA by using ammonium sulfate precipitation. The antiserum showed almost no cross-reactivity with a variety of other nucleotides and riboses. But, the level of cross-reactivity of 5'-isobutylthioadenosine (SIBA) was high. These results showed the importance of hydrophobicity adjacent to the 5'-OH for determining antigenicity. The lower limit of detection by this assay was 100 fmol of MTA per tube. Using this assay. MTA levels were more easily and precisely determined in biological samples when compared with HPLC analysis. The RIA procedure is less time consuming. More than 24 analyses can be carried out in 2 h and required only a very small amount of sample ($20{\mu}l$ serum). In ELISA, biotin conjugated MTA-BSA was used as the labelled MTA. The sensitivity limit of this assay was lower than 100 pmol.

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Development of an ELISA for the Detection of Fenazaquin Residues in Fruits

  • Lee, Jae-Koo;Kim, Yun-Jung;Lee, Eun-Young;Kim, Dae-Kyu;Kyung, Kee-Sung
    • Journal of Applied Biological Chemistry
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    • 제48권1호
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    • pp.16-25
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    • 2005
  • To develop an enzyme-linked immunosorbent assay (ELISA) for the detection of the residues of the acaricide fenazaquin, five haptens were synthesized and assessed. A competitive indirect format was used with polyclonal antibodies. Under an optimized condition using the selected rabbit C antiserum, an $IC_{50}$ of $96.97\;ng{\cdot}ml^{-1}$, the detection range of $14.9{\sim}631\;ng{\cdot}ml^{-1}$, and the lowest detection limit of $8\;ng{\cdot}ml^{-1}$ were obtained. Some structurally related compounds of practical use showed low crossreactivities to the antibody. Highest cross-reactivity observed with hapten IV indicates that the antiserum C recognizes very well quinazoline ring, 4-tert-butylphenyl, and an adequate length of spacer arm. The length of spacer arm affected recognition of quinazoline ring and 4-tert-butylphenyl moieties. When applied to apple and pear, recoveries were within acceptable ranges of $93.18{\sim}104.77%$ (n = 4) and $79.40{\sim}111.95%$ (n = 4), respectively.

신경괴사증바이러스(nervous necrosis virus, RGNNV genotype)에 대한 단클론 항체 생산 (Production of Monoclonal Antibodies Against Nervous Necrosis Virus (NNV, RGNNV genotype))

  • 김위식;김시우;오명주
    • 한국수산과학회지
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    • 제51권3호
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    • pp.328-331
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    • 2018
  • We developed and subsequently characterized mouse monoclonal antibodies (MAbs) against nervous necrosis virus (NNV, RGNNV genotype). We established six hybridoma clones secreting MAbs against NNV antigen: 2B1, 2B11, 2C12, 13C1-1, 13C1-2 and 14D11. All six MAbs belonged to the IgG2a isotype with a kappa light chain and their reactivity recognized against the 41 kDa coat protein of NNV by Western blot analysis. The affinity constants of the six MAbs were measured by enzyme-linked immunosorbent assay (ELISA). All six MAbs reacted with two NNV isolates (SgNag05 and Gemunodo06), while no reactivity was observed with five know fish viruses, namely marine birnavirus, infectious pancreatic necrosis virus, viral hemorrhagic septicemia virus, hirame rhabdovirus, and infectious hematopoietic necrosis virus. Moreover, high ELISA optical density (OD) values (0.87-1.42) were observed in the brain tissues of NNV-infected sevenband grouper, while low OD values (less than 0.12) were recorded in the brain tissues of uninfected fish. These results suggest that these six MAbs are highly competent and useful for the detection of NNV with the RGNNV genotype.

Marine birnavirus (MABV)에 대한 단클론 항체 생산 (Production of monoclonal antibodies against marine birnavirus)

  • 공경희;오명주;김위식
    • 한국어병학회지
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    • 제33권2호
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    • pp.171-175
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    • 2020
  • We developed and subsequently characterized mouse monoclonal antibodies (mAbs) against marine birnavirus (MABV). Eight hybridoma clones secreting mAbs against MABV were established. All eight mAbs (8G6, 11C3, 15E3, 17H6, 32A6, 35A7, 38B5, and 47E3) were reacted with viral protein 3 of MABV in MABV-infected CHSE-214, whereas, no reactivity was observed in normal CHSE-214 by western blot analysis. Moreover, these eight mAbs were strongly reacted with MABV, and no cross-reactivity has been observed against other five fish viruses (hirame rhabdovirus, infectious hematopoietic necrosis virus, nervous necrosis virus, spring viraemia of carp virus, and viral hemorrhagic septicemia virus), although five mAb (11C3, 15E3, 17H6, 32A6, and 38B5) reacted with both MABV and infectious pancreatic necrosis virus by enzyme linked immunosorbent assay (ELISA). These results indicate that the mAbs can be of value in MABV detection.

Infectious hematopoietic necrosis virus (IHNV)에 대한 단클론 항체 생산 (Production of monoclonal antibodies against infectious hematopoietic necrosis virus (IHNV))

  • 공경희;오명주;김춘섭;김위식
    • 한국어병학회지
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    • 제36권2호
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    • pp.389-394
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    • 2023
  • Infectious hematopoietic necrosis virus (IHNV) is s significant viral pathogen affecting cultured rainbow trout (Oncorhynchus mykiss) in Korea. In this study, five monoclonal antibodies (mAbs) (IHNV-1, 2, 3, 4, and 5) were produced using purified IHNV. Reactivities of these mAbs were analyzed by western blot (WB), enzyme-linked immunosorbent assay (ELISA), and indirect fluorescent antibody test (IFAT). These mAbs recognized glycoprotein (69 kDa, IHNV-1), nucleocapsid protein (39 kDa, IHNV-3, 4, and 5), or phosphoprotein (27 kDa, IHNV-2) of IHNV by WB analysis. ELISA results indicated that these five mAbs were specific to IHNV without showing any cross-reactivity against other fish viruses (hirame rhabdovirus, infectious pancreatic necrosis virus, and viral hemorrhagic septicemia virus). IFAT demonstrated specific fluorescence signals of IHNV-infected epithelioma papulosum cyprini (EPC) cells, whereas no reactivity of normal EPC cells was observed. These mAbs can be very useful for immuno-diagnosis of IHNV infection.

Molecular Orbital Theory on Cellulolytic Reactivity Between pNP-Cellooligosccharides and ${\beta}$-Glucosidase from Cellulomonas uda CS1-1

  • Yoon, Min-Ho;Nam, Yun-Kyu;Choi, Woo-Young;Sung, Nack-Do
    • Journal of Microbiology and Biotechnology
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    • 제17권11호
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    • pp.1789-1796
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    • 2007
  • A ${\beta}$-glucosidase with the molecular mass of 160,000 Da was purified to homogeneity from cell extract of a cellulolytic bacterium, Cellulomonas uda CS1-1. The kinetic parameters ($K_m$ and $V_{max}$) of the enzyme were determined with pNP-cellooligosccharides (DP 1-5) and cellobiose. The molecular orbital theoretical studies on the cellulolytic reactivity between the pNP-cellooligosaccharides as substrate (S) molecules and the purified ${\beta}$-glucosidase (E) were conducted by applying the frontier molecular orbital (FMO) interaction theory. The results of the FMO interaction between E and S molecules verified that the first stage of the reaction was induced by exocyclic cleavage, which occurred in an electrophilic reaction based on a strong charge-controlled reaction between the highest occupied molecular orbital (HOMO) energy of the S molecule and the lowest occupied molecular orbital (LUMO) energy of the hydronium ion ($H_3O^+$), more than endocyclic cleavage, whereas a nucleophilic substitution reaction was induced by an orbital-controlled reaction between the LUMO energy of the oxonium ion ($SH^+$) protonated to the S molecule and the HOMO energy of the $H_2O_2$ molecule. A hypothetic reaction route was proposed with the experimental results in which the enzymatic acid-catalyst hydrolysis reaction of E and S molecules would be progressed via $SN_1$ and $SN_2$ reactions. In addition, the quantitative structure-activity relationships (QSARs) between these kinetic parameters showed that $K_m$ has a significant correlation with hydrophobicity (logP), and specific activity has with dipole moment, respectively.

돼지 지방세포 원형질막 단백질에 대한 다클론항체의 생산 및 이용에 관한 연구 (Studies on the Development and Utilization of Polyclonal Antibodies Against Swine Adipocyte Plasma Membrane Proteins)

  • 백경훈;곽태효;오영숙;최창원;정근기;최창본
    • Journal of Animal Science and Technology
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    • 제47권1호
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    • pp.19-28
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    • 2005
  • The objectives of the current study were to develop polyclonal antibodies in sheep against adipocyte plasma membrane(APM) proteins isolated from swine, to investigate tissue specificity, and to determine cytotoxic effects of antiserum on swine adipocytes. Plasma membrane proteins from adipocyte, brain, heart, kidney, liver, and spleen were isolated using a 32% sucrose gradient. Adult male sheep was immunized three times at three week interval with the purified swine APM proteins. Antiserum was taken from immunized sheep at 10, 12, and 14 days after the third immunization. Antiserum expressed strong reactivity with APM proteins determined by enzyme-linked immunosorbent assay(ELISA), and the reactivity could be detected at dilutions in excess of 1 : 81,000. Antiserum showed very low binding affinity with proteins isolated from brain, heart, kidney, liver, or spleen. Tissue specificity of the antiserum was reconfirmed by Western immunoblotting using anti-sheep immunoglobulin G•alkalinephosphatase conjugate as a secondary antibody. The reactivity of antiserum to the external surface of fixed swine adipocytes was confmned by an immunohistochemical technique using anti-sheep immunoglobulin G-FITC. Confluent swine adipocytes in culture were lysed by antiserum treatment and cytosolie lactate dehydrogenase(LDH) was released as a dose-dependent patterns while adipocytes treated with normal sheep serum maintained their integrity and expressed low level of LDH. These results implicate that fat contents in the pigs can be reduced by immunological methods.

Individual expression and processing of hepatitis C virus E1/E2 epitopes-based DNA vaccine candidate in healthy humans' peripheral blood mononuclear cells

  • Rola Nadeem;Amany Sayed Maghraby;Dina Nadeem Abd-Elshafy;Ahmed Barakat Barakat;Mahmoud Mohamed Bahgat
    • Clinical and Experimental Vaccine Research
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    • 제12권1호
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    • pp.47-59
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    • 2023
  • Purpose: The development and study of hepatitis C virus (HCV) vaccine candidates' individualized responses are of great importance. Here we report on an HCV DNA vaccine candidate based on selected envelope (E1/E2) epitopes. Besides, we assessed its expression and processing in human peripheral blood mononuclear cells (PBMCs) and in vivo cellular response in mice. Materials and Methods: HCV E1/E2 DNA construct (EC) was designed. The antigen expression of EC was assayed in PBMCs of five HCV-uninfected donors via a real-time quantitative polymerase chain reaction. Serum samples from 20 HCV antibody-positive patients were used to detect each individual PBMCs expressed antigens via enzyme-linked immunosorbent assay. Two groups, five Swiss albino mice each, were immunized with the EC or a control construct. The absolute count of lymph nodes' CD4+ and CD8+ T-lymphocytes was assessed. Results: Donors' PBMCs showed different levels of EC expression, ranging between 0.83-2.61-fold in four donors, while donor-3 showed 34.53-fold expression. The antigens expressed in PBMCs were significantly reactive to the 20 HCV antibody repertoire (all p=0.0001). All showed comparable reactivity except for donor-3 showing the lowest reactivity level. The absolute count % of the CD4+ T-cell significantly increased in four of the five EC-immunized mice compared to the control group (p=0.03). No significant difference in CD8+ T-cells % was observed (p=0.89). Conclusion: The inter-individual variation in antigen expression and processing dominance was evident, showing independence in individuals' antigen expression and reactivity levels to antibodies. The described vaccine candidate might result in a promising natural immune response with a possibility of CD4+ T-cell early priming.

면양을 이용한 돼지 지방제포 원형질막 단백질 특이 항체의 생산 (Production of Polyclonal Antibodies Specific to Porcine Adipocyte Plasma Membrane Proteins in Sheep)

  • 최창본;이명진;권은진
    • 대한의생명과학회지
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    • 제4권1호
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    • pp.57-63
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    • 1998
  • 본 연구는 돼지 지방세포 원형질막 단백질에 대한 항체를 면양에서 생산하고 생산된 항체의 역가 및 조직특이성을 조사하기 위하여 실시되었다. 지방세포, 뇌, 심장, 신장, 간장 및 비장으로부터 원형질막 단백질을 추출하였으며, 그중 지방세포로부터 분리한 원형질막 단백질을 면양(체중 40kg)에 3주 간격으로 3회 면역 접종시켰다. 면역접종 전, 3차 면역접종 후 10일 (AS-1), 12일 (AS-2)및 14일 (AS-3)째에 각각 면양의 경정맥으로부터 혈액을 채취하여 혈청을 분리하였다. 항체의 역가 및 기타 조직과의 교차반응성은 enzyme-linked immunosorbent assay (ELISA)로 측정하였다. 면양에서 생산된 돼지 지방세포 원형질막 단백질에 대한 항혈청은 지방세포 원형질막 단백질과 강한 항원-항체 반응을 나타내었다. 항혈청의 교차반응성을 조사한 결과, 기타 조직의 원형질막 단백질과는 매우 미약한 반응을 나타낸 반면 지방세포 원형질막 단백질과는 강한 반응을 나타내었다. 이러한 항혈청의 지방세포 원형질막 단백질과의 조직특이적인 반응은 anti-sheep immunoglobulin G-horseradish peroxidase conjugate를 2차 항체로 이용한 immunoblot에 의해서도 재확인되었다. 이상의 결과, 면양으로부터 생산된 돼지 지방세포 원형질막 단백질에 대한 항체는 높은 역가를 지니고 있었으며, 지방세포 원형질막 단백질에 특이적으로 작용함을 알 수 있었다.

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