• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.3071-3076
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• 2014

Proteomic analyses of the excretory/secretory proteins from the RH strain of Toxoplasma gondii have been performed to understand their functions in the host-parasite interaction. A total of 34 proteins were identified from LC/MS/MS analysis and their abundance was estimated by spectral counting methods. Among them, 8 species of micronemal proteins (MICs), 2 species of rhoptry proteins (ROPs), and 6 species of dense granular proteins (GRAs) were confirmed. Besides these, 18 species of protein were newly identified, and their cellular functions were estimated from sequence analysis. The three most abundant of the 34 identified extractor/secretory proteins-GRA1, GRA7 and GRA2-were confirmed to be highly expressed in T. gondii using the spectral count method. This phenomenon is another demonstration of the importance of GRA proteins for the penetration and survival of T. gondii.

• Parasites, Hosts and Diseases
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• 제57권4호
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• pp.379-387
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• 2019

Clonorchis sinensis is a carcinogenic human liver fluke that promotes hepatic inflammatory environments via direct contact or through their excretory-secretory products (ESPs), subsequently leading to cholangitis, periductal fibrosis, liver cirrhosis, and even cholangiocarcinoma (CCA). This study was conducted to examine the host inflammatory responses to C. sinensis ESPs and their putative protein components selected from C. sinensis expressed sequenced tag (EST) pool databases, including $TGF-{\beta}$ receptor interacting protein 1(CsTRIP1), legumain (CsLeg), and growth factor binding protein 2 (CsGrb2). Treatment of CCA cells (HuCCT1) with the ESPs or bacterial recombinant C. sinensis proteins differentially promoted the secretion of proinflammatory cytokines ($IL-1{\beta}$, IL-6, and $TNF-{\alpha}$) as well as anti-inflammatory cytokines (IL-10, $TGF-{\beta}1$, and $TGF-{\beta}2$) in a time-dependent manner. In particular, recombinant C. sinensis protein treatment resulted in increase (at maximum) of ~7-fold in $TGF-{\beta}1$, ~30-fold in $TGF-{\beta}2$, and ~3-fold in $TNF-{\alpha}$ compared with the increase produced by ESPs, indicating that CsTrip1, CsLeg, and CsGrb2 function as strong inducers for secretion of these cytokines in host cells. These results suggest that C. sinensis ESPs contribute to the immunopathological response in host cells, leading to clonorchiasis-associated hepatobiliary abnormalities of greater severity.

• 대한수의학회지
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• 제44권3호
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• pp.455-462
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• 2004

Change in ${\beta}$-tubulin nucleic acid and protein sequences was the only known difference between Haemonchus contortus fenbendazole (FBZ)-resistant and -susceptible isolates. This change was sufficient to determine the pathologic effect induced by FBZ treatment. This research was initiated to investigate further differences from these two isolates. Since ${\beta}$-tubulin is involved in formation of microtubule, which has functions in secretory vesicle transport, DNase activities from excretory/secretory products (ESP) of the two isolates were compared, based on pH, sensitivity to DNase inhibitors, molecular masses and production of 3'-OH. The most significant difference detected was that a 38.5 kDa DNase activity was identified from ESP of H. contortus FBZ-susceptible isolates but not from those of H. contortus FBZ-resistant isolates. However, it was shown that the 38.5 kDa DNase is expressed with similar level of activity in intestine and whole worm of H. contortus FBZ-resistant and -susceptible isolates. This result demonstrated that the secretory transport pathway of the 38.5 kDa DNase was inhibited by unknown mechanisms, which may be related with ${\beta}$-tubulin sequence change in FBZ-resistant isolates. Other DNases of 34, 36 and 37 kDa were detected from ESP of both H. contortus FBZ-resistant and -susceptible isolates. Overall DNase activities found from ESP of these two isolates were not inhibited by 10 mM EDTA at pH 5.0, but largely inhibited by pH 7.0. In addition, DNase activities in two isolates produced DNA fragments with mixtures of 3'- hydroxyls (OH) and 3'-phosphates (P) at each pH although the 3'-end labeling ratios at pH 5.0 and 7.0 were shown different. Identification of inhibition of the 38.5 kDa DNase secretion in FBZ-resistant isolates suggests existence of further differences, in addition to ${\beta}$-tubulin sequence change, in two isolates. This shows complex effect of FBZ on H. contortus biological mechanisms.

• Parasites, Hosts and Diseases
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• 제45권1호
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• pp.19-26
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• 2007

This study describes the isolation of a Toxocara canis species-specific excretory-secretory(ES) antigen and the development of an enzyme-linked immunosorbent assay(ELISA) based on this antigen. Analysis of the ES antigens of T. canis, Toxocara vitulorum, Ascaris lumbricoides and Necator americanus larval antigen was performed by SDS-PAGE followed by western blotting. A 57 kDa T. canis-specific antibody fraction(TcES-57) was identified by western blotting and labelling with anti-Toxocara antibodies(from experimental rabbits and human patients) and tracing with anti-human or anti-rabbit peroxidase conjugate. No protein fraction of 57 kDa was detected in ES or larval antigens collected from T. canis, T. vitulorum, A. lumbricoides and N. americanus. Using TcES-57, a specific anti-serum was produced in rabbits and a double sandwich ELISA was developed. This test was validated using known seropositive sera from toxocariasis patients, sera from A. lumbricoides or N. americanus patients, and 50 serum samples from cats. These tests revealed that TcES-57 antigen is specific to T. canis infection and does not cross react with sera of other related infections. Thus, ELISA based on TcES-57 antigen was proven to be an effective tool in the diagnosis of toxocariasis and studies on the role of T. canis in the epidemiology of human toxocariasis.

• Parasites, Hosts and Diseases
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• 제30권3호
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• pp.227-230
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• 1992

스파르가눔증의 항체검사에서 항원으로 사용하는 스파르가눔 충체추출액의 구성 단백질 중, 환자혈청과 반응 시켜 관찰한 바, 분자량 36 및 31 kDa인 단백질이 항원성이 높았다. 또한 이 두가지 단백질은 스파르가눔 충체의 표피와 표피세포에 분포하여 충체 외부로 분비되는 항원일 것으로 추정하였다. 이 연구단보에서는 이들 두가지 단백질이 분비배설항원에 나타남을 증명하고자 스파르가눔을 $4^{\circ}C{\;}및{\;}37^{\circ}C$ 생리식염수에 30분~100시간 동안 배양하여 분비배설항원을 만들고, 분비배설항원내 단백질 분비량, 단백질의 조성 미치 단백질분해효소의 활성을 각각 관찰하였다. 충체 g당 분비배설항원의 단백질량은 관찰 범위안에서 배양온도에 관계없이 평균 7.7 mg이었다. SDS-폴리아크릴아미드 젤 전기영동상 분비배설항원의 단백질 구성은 분자량 66 kDa 이상인 단백질에서 차이가 있을 뿐 충체추출액의 것과 거의 유사하였다. 물론 분자량 36 및 31 kDa인 단백질도 분비배설항원의 주 구성성분이었다. 분비배설항원의 단백질분해효소 비활성도(比活性度)는 2.9~5.3 units/mg으로 충체추출액의 것과 차이가 없었다. 이미 보고된 스파르가눔의 cysteine protease가 체외로 분비되는 효소라는 것이 사실이라고 추정하게 하는 결과로 생각하였다.

• Parasites, Hosts and Diseases
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• 제50권2호
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• pp.165-171
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• 2012

Larval excretory-secretory products of Anisakis simplex are known to cause allergic reactions in humans. A cDNA library of A. simplex 3rd-stage larvae (L3) was immunoscreened with polyclonal rabbit serum raised against A. simplex L3 excretory-secretory products to identify an antigen that elicits the immune response. One cDNA clone, designated as ${\alpha}$-methylacyl CoA racemase (Amacr) contained a 1,412 bp cDNA transcript with a single open reading frame that encoded 418 amino acids. A. simplex Amacr showed a high degree of homology compared to Amacr orthologs from other species. Amacr mRNA was highly and constitutively expressed regardless of temperature (10-$40^{\circ}C$) and time (24-48 hr). Immunohistochemical analysis revealed that Amacr was expressed mainly in the ventriculus of A. simplex larvae. The Amacr protein produced in large quantities from the ventriculus is probably responsible for many functions in the development and growth of A. simplex larvae.

• 대한의생명과학회지
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• 제3권2호
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• pp.89-94
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• 1997

가토에게 간흡충을 감염시키고 3개월 후 거살한 다음 간흡충의 충체, 간흡충의 분비배설액 그리고 간토의 담즙을 조항원으로 제조한 후 이에 대한 항원단백질의 구성물질을 분석하였다. 그리고 cysteine계 면역억제제인 E-64와 serine계 면역억제제인 PMSF를 첨가하였을 때 단백질 구성물질의 발현 양상을 관찰하였다. 실험적으로 가토에서 얻은 간흡충 성충의 조항원은 200-9 kDa의 범위에서 26개의 분획 을 관찰하였으며, 간흡충 성충 조항원에 cysteine계 단백질분해효소 억제제인 E-64를 첨거하였을 때 잘 보존하여 200-9 kDa의 범위에서 29개의 분획을 관찰하였다. 간흡충 성충의 분비배설액 조항원은 200-9 kDa범위에서 27개의 분획이 관찰되었으며, cysteine계 단백질분해효소 억제제인 E-64를 첨거하였을 때 잘 보존하여 200-9 kDa의 범위에서 29개의 분획이 관찰되었다. 그리고 간흡충을 감염시킨 가토의 담즙 조항원은 200-9 kDa의 범위에서 19개의 분획이 관찰되었으며, serine 계 단백질분해효소인 PMSF를 첨거하였을 때 200-10 kDa의 범위에서 22개의 분획이 관찰되었으나, cysteine계 단백질분해효소인 E-64에서도 비슷한 양상을 보였다. 대조군인 건강 가토의 담즙 조항원은 200-10 kDa의 범위에서 22개의 분획이 관찰되었으며, serine계 단백질분해효소 억제제인 PMSF를 첨가하였을 때 잘 보존하여 200-12 kDa의 범위에서 23개의 분획이 관찰되었다. 앞으로 각 항원에 대한 면역학적 특징 및 단세포군 항체에 대한 구체적인 규명이 계속되어야겠다.

• Parasites, Hosts and Diseases
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• 제41권3호
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• pp.165-169
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• 2003

This study describes the characterization of 80 kDa pretense showing gelationlytic property among three pretenses in the excretory/secretory proteins (ESP) from Toxoplasma gondii. The pretense activity was detected in the ESP but not in the somatic extract of RH tachyzoites. This pretense was active only in the presence of calcium ion but not other divalent cationic ions such as $Cu^{2+},{\;}Zn^{2+},{\;}Mg^{2+},{\;}and{\;}$Mn^{2+}$, implying that $Ca^{2+}$ is critical factor for the activation of the protease. The 80 kDa pretense was optimally active at pH 7.5. Its gelatinolytic activity was maximal at $37^{\circ}C$, and significant level of enzyme activity of the pretense remained after heat treatment at $56^{\circ}C$ for 30 min or $100^{\circ}C$ for 10 min, This thermostable enzyme was strongly inhibited by metal chelators, i.e., EDTA, EGTA, and 11 10-phenanthroline. Thus, the 80 kDa pretense in the ESP secreted by T. gondii was classified as a calcium dependent neutral metalloprotease.

• 대한수의학회지
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• 제44권4호
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• pp.625-635
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• 2004

Trichnuris suis does not excrete eggs during larval stage as well as in particular adult stage, It is impossible to diagnose by use of fecal examination method in those periods. Therefore, serological diagnostic method can be very useful for those stages. In order to produce monoclonal antibody, specific somatic and secretory-excretory (SE) antigens of T. suis were identified and analyzed by SDS-PAGE and Western blot. Monoclonal antibody-producing hybridoma cells were cloned, which were made of popliteal lymph node of BALB/c mice immunized with a 45 kDa somatic antigen of T. suis. Five clones (1B9, 2C4, n2C5, 2D7 and 2D8) showing strong responses to T. suis antigens were selected and the isotype identified. All monoclonal antibodies were IgG1 isotype and the light chains were k chain. Established monoclonal antibodies reacted specifically to somatic and SE antigens of T. suis and did not cross-reacted to antigens of ascaris suum, trichuris vulpis, or Trichinella spiralis. The sensitivity of somatic and SE antigens against these monoclonal antibodies were significant (p<0.01) associated with those of positive and negative sera.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.637-645
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• 2011

Production of recombinant proteins by excretory expression has many advantages over intracellular expression in Escherichia coli. Hyperexpression of a secretory exoglucanase, Exg, of Cellulomonas fimi was previously shown to saturate the SecYEG pathway and result in dramatic cell death of E. coli. In this study, we demonstrated that overexpression of the PspA in the JM101(pM1VegGcexL-pspA) strain enhanced excretion of Exg to 1.65 U/ml using shake-flask cultivation, which was 80% higher than the highest yield previously obtained from the optimized JM101(pM1VegGcexL) strain. A much higher excreted Exg activity of 4.5 U/ml was further achieved with high cell density cultivation using rich media. Furthermore, we showed that the PspA overexpression strain enjoyed an elevated critical value (CV), which was defined as the largest quotient between the intracellular unprocessed precursor and its secreted mature counterpart that was still tolerable by the host cells prior to the onset of cell death, improving from the previously determined CV of 20/80 to the currently achieved CV of 45/55 for Exg. The results suggested that the PspA overexpression strain might tolerate a higher level of precursor Exg making use of the SecYEG pathway for secretion. The reduced lethal effect might be attributable to the overexpressed PspA, which was postulated to be able to reduce membrane depolarization and damage. Our findings introduce a novel strategy of the combined application of metabolic engineering and construct optimization to the attainment of the best possible E. coli producers for secretory/excretory production of recombinant proteins, using Exg as the model protein.