• 제목/요약/키워드: catalytic factor

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Collagen-Induced Arthritis Analysis in Rhbdf2 Knockout Mouse

  • Lee, Min-Young;Kang, Ju-Seong;Go, Ryeo-Eun;Byun, Yong-Sub;Wi, Young Jin;Hwang, Kyung-A;Choi, Jae-Hoon;Kim, Hyoung-Chin;Choi, Kyung-Chul;Nam, Ki-Hoan
    • Biomolecules & Therapeutics
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    • 제26권3호
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    • pp.298-305
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    • 2018
  • Rhomboid family member 2 gene (Rhbdf2) is an inactive homologue lacking essential catalytic residues of rhomboid intramembrane serine proteases. The protein is necessary for maturation of tumor necrosis factor-alpha ($TNF-{\alpha}$) converting enzyme, which is the molecule responsible for the release of $TNF-{\alpha}$. In this study, Rhbdf2 knockout (KO) mice were produced by CRISPR/CAS9. To see the effects of the failure of $TNF-{\alpha}$ release induced by Rhbdf2 gene KO, collagen-induced arthritis (CIA), which is the representative $TNF-{\alpha}$ related disease, was induced in the Rhbdf2 mutant mouse using chicken collagen type II. The severity of the CIA was measured by traditional clinical scores and histopathological analysis of hind limb joints. A rota-rod test and grip strength test were employed to evaluate the severity of CIA based on losses of physical functions. The results indicated that Rhbdf2 mutant mice showed clear alleviation of the clinical severity of CIA as demonstrated by the significantly lower severity indexes. Moreover, a grip strength test was shown to be useful for the evaluation of physical functional losses by CIA. Overall, the results showed that the Rhbdf2 gene has a significant effect on the induction of CIA, which is related to $TNF-{\alpha}$.

The Role and Regulation of MCL-1 Proteins in Apoptosis Pathway

  • Bae, Jeehyeon
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2002년도 창립10주년기념 및 국립독성연구원 의약품동등성평가부서 신설기념 국재학술대회:생물학적 동등성과 의약품 개발 전략을 위한 국제심포지움
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    • pp.113-113
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    • 2002
  • Phylogenetically conserved Bcl-2 family proteins play a pivotal role in the regulation of apoptosis from virus to human. Members of the Bcl-2 family consist of antiapoptotic proteins such as Bcl-2, Bcl-xL, and Bcl-w, and proapoptotic proteins such as BAD, Bax, BOD, and Bok. It has been proposed that anti- and proapoptotic Bcl-2 proteins regulate cell death by binding to each other and forming heterodimers. A delicate balance between anti- and proapoptotic Bcl-2 family members exists in each cell and the relative concentration of these two groups of proteins determines whether the cell survives or undergoes apoptosis. Mcl-1 (Myeloid cell :leukemia-1) is a member of the Bcl-2 family proteins and was originally cloned as a differentiation-induced early gene that was activated in the human myeloblastic leukemia cell line, ML-1 . Mcl-1 is expressed in a wide variety of tissues and cells including neoplastic ones. We recently identified a short splicing variant of Mcl-1 short (Mcl-IS) and designated the known Mcl-1 as Mcl-1 long (Mcl-lL). Mcl-lL protein exhibits antiapoptotic activity and possesses the BH (Bcl-2 homology) 1, BH2, BH3, and transmembrane (TM) domains found in related Bcl-2 proteins. In contrast, Mcl-1 S is a BH3 domain-only proapoptotic protein that heterodimerizes with Mcl-lL. Although both Mc1-lL and Mcl-lS proteins contain BH domains fecund in other Bcl-2 family proteins, they are distinguished by their unusually long N-terminal sequences containing PEST (proline, glutamic acid, serine, and threonine) motifs, four pairs of arginine residues, and alanine- and glycine-rich regions. In addition, the expression pattern of Mcl-1 protein is different from that of Bcl-2 suggesting a unique role (or Mcl-1 in apoptosis regulation. Tankyrasel (TRF1-interacting, ankyrin-related ADP-related polymerasel) was originally isolated based on its binding to TRF 1 (telomeric repeat binding factor-1) and contains the sterile alpha motif (SAM) module, 24 ankyrin (ANK) repeats, and the catalytic domain of poly(adenosine diphosphate-ribose) polymerase (PARP). Previous studies showed that tankyrasel promotes telomere elongation in human cells presumably by inhibiting TRFI though its poly(ADP-ribosyl)action by tankyrasel . In addition, tankyrasel poly(ADP-ribosyl)ates Insulin-responsive amino peptidase (IRAP), a resident protein of GLUT4 vesicles, and insulin stimulates the PARP activity of tankyrase1 through its phosphorylation by mitogen-activated protein kinase (MAPK). ADP-ribosylation is a posttranslational modification that usually results in a loss of protein activity presumably by enhancing protein turnover. However, little information is available regarding the physiological function(s) of tankyrase1 other than as a PARP enzyme. In the present study, we found tankyrasel as a specific-binding protein of Mcl-1 Overexpression of tankyrasel led to the inhibition of both the apoptotic activity of Mel-lS and the survival action of Mcl-lL in mammalian cells. Unlike other known tankyrasel-interacting proteins, tankyrasel did not poly(ADP-ribosyl)ate either of the Mcl-1 proteins despite its ability to decrease Mcl-1 proteins expression following coexpression. Therefore, this study provides a novel mechanism to regulate Mcl-1-modulated apoptosis in which tankyrasel downregulates the expression of Mcl-1 proteins without the involvement of its ADP-ribosylation activity.

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알칼리형 연료전지에서 산소환원에 미치는 촉매 특성 연구 I. La0.6Sr0.4Co1-xFexO3의 합성과 산소환원반응 (A Study on the Catalytic Characteristics of Oxygen Reduction in an Alkaline Fuel Cell I. Synthesis of La0.6Sr0.4Co1-xFexO3 and Reduction Reaction of Oxygen)

  • 문형대;이호인
    • 공업화학
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    • 제7권3호
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    • pp.543-553
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    • 1996
  • 산소전극 촉매로서 페롭스카이트형 산화물을 사용하여 알칼리형 연료전지에서의 산소환원반응에 관하여 연구하였다. 능금산(malic acid)을 사용하여 고표면적의 페롭스카이트형 $La_{0.6}Sr_{0.4}Co_{1-x}Fe_xO_3$(x=0.00, 0.01, 0.10, 0.20, 0.35 및 0.50) 산화물을 제조하였으며, Fe 치환량과 암모니아수 첨가량에 따른 XRD 구조와 비표면적의 변화를 고찰하여 Fe와 암모니아간에 생성되어지는 착화합물이 페롭스카이트로의 구조안정화와 비표면적 증대의 주요임을 알았다. 그리고 페롭스카이트 단일상을 얻기 위해서는 다단계 승온처리가 필요했으며, XRD 실험결과 단순 정입방체상이 형성됨을 확인하였다. $La_{0.6}Sr_{0.4}Co_{1-x}Fe_xO_3$ 산화물을 촉매로 사용한 알칼리형 연료전지용 산소전극의 산소환원반응활성을 측정하기 위하여 순환 전압-전류법, 정전압-전류법, 전류단절법 등을 이용하였다. $La_{0.6}Sr_{0.4}Co_{1-x}Fe_xO_3$ 산화물에서 Fe의 치환비가 증가함에 따라, x=0.01에서 최소, x=0.20와 0.35 사이에서 최대의 산소환원활성(전류밀도)을 보였으며, 이와 같은 경향은 표면적의 변화와 무관하였다.

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생쥐 Wee1 인산화효소들의 각 도메인의 역할에 관한 연구 (The Roles of Amino and Carboxyl Domains in the Mouse Wee1 Kinases)

  • 한승진
    • 생명과학회지
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    • 제18권1호
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    • pp.114-119
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    • 2008
  • Wee1 인산화효소는 세포주기 조절의 핵심 단백질인 cdc2/cyclinB 복합체를 인산화하여 활성을 억제, 조절하는 주요한 효소이다. 지금까지 포유동물에서는 Wee1A, Wee1B 그리고 Myt1의 세 가지 효소가 발견되었다. Wee1 인산화효소의 조절기작을 연구하기 위하여 생쥐의 Wee1A와 Wee1B를 발톱개구리의 난자에 주사한 후 단백질의 변형을 관찰하였다. 이 세포주기 과정에서 두 효소는 모두 인산화 되었으며, Wee1A단백질은 분해되는 것을 관찰 할 수 있었다. 또한 세포외 인산화 방법을 통하여 Wee1A가 PKA와 Akt에 의해 인산화됨을 확인하였다. 이러한 Wee1 인산화효소의 인산화와 단백질 안정성에 영향을 미치는 단백질 내의 부위를 살펴보고자, Wee1A와 Wee1B의 아미노 도메인과 카르복실 도메인을 서로 치환한 단백질을 제조하여 개구리 난자에 주사하고 인산화 정도와 단백질의 안정성을 조사하였을 때, Wee1A의 아미노 도메인이 단백질의 인산화와 안정화에 중요한 영향을 미친다는 것을 규명하였다. 그리고 Wee1B의 아미노 도메인과 Wee1A의 카르복실 도메인은 효소의 활성을 조절하는 역할을 한다.

아라키돈산과 철 유도성 산화적 스트레스에 대한 금앵자(金櫻子) 열수 추출물의 간세포 보호 효능 (Water Extract of Rosa laevigata Michx. Protects Hepatocytes from Arachidonic Acid and Iron-mediated Oxidative Stress)

  • 고해리;제갈경환;송시연;김난이;강지원;변성희;김영우;조일제;김상찬
    • 대한본초학회지
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    • 제30권6호
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    • pp.7-15
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    • 2015
  • Objectives : Rosa laevigata Michx. has been used for the treatment of renal disease in traditional Korean medicine. In this study, we investigated cytoprotective effect of R. laevigata water extract (RLE) against oxidative stress induced by arachidonic acid (AA) + iron.Methods : To evaluate the protective effects of RLE against AA + iron-induced oxidative stress in HepG2 cell, cell viability and changes on apoptosis-related proteins were assessed by MTT and immunoblot analyses. The effects of RLE on reduced glutathione level, production of reactive oxygen species and mitochondrial membrane potential were also monitored. Furthermore, to verify underlying molecular mechanism, NF-E2-related factor 2 (Nrf2) was examined by immunoblot analysis. Additionally, Nrf2 transactivation and its downstream target genes expression were also determined by reporter gene and realtime RT-PCR analyses.Results : RLE pretreatment (30-300 μg/ml) prevented cells from AA + iron-mediated cell death in a concentration dependent manner. In addition, 100 μg/ml RLE inhibited AA + iron-induced glutathione depletion, reactive oxygen species production and mitochondrial dysfunction. RLE accumulated nuclear Nrf2 and also transactivated Nrf2, which was evidenced by antioxidant response element- and glutathione S-transferase A2-driven luciferase activities and mRNA level of glutamate-cysteine ligase catalytic subunit, NAD(P)H:quinone oxidoreductase 1 and sestrin 2. Moreover, protective effect of RLE against AA + iron was abolished in Nrf2 knockout cells.Conclusions : These results indicate that RLE has the ability to protect hepatocyte against oxidative stress through Nrf2 activation.

E. coli에서 발현된 human HtrA1 단백질의 정제와 HtrA1의 serine protease 활성 조건에 관한 연구 (Purification of Human HtrA1 Expressed in E. coli and Characterization of Its Serine Protease Activity)

  • 김경희;김상수;김구영;임향숙
    • 생명과학회지
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    • 제16권7호
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    • pp.1133-1140
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    • 2006
  • E. coli HtrA (High temperature requirement protein A)의 human homologue 중 하나인 HtrA1은 IGFBP를 절단하여 IGF의 활동을 조절하는 serine protease으로 알려졌다. HtrA1의 serine protease 활성이 여러 질병의 발병 mechanism과 연관성을 가진 것으로 예상되고 있지만, 이런 상관관계를 밝히기 위해서 기본적으로 필요한 다량의 HtrA1 단백질의 발현 및 정제조건과 HtrA1 serine protease의 최적 활성조건이 확립되어 있지 않은 상황이다. 따라서 본 연구에서는 pGEX 시스템을 이용하여 E. coli에서 mature HtrA1인 ${\Delta}149(WT)$와 catalytic site mutant인 ${\Delta}149(S328A)$를 85%의 순도로 1 liter 배양 시, 정제된 단백질을 각각 $400{\mu}g,\;520{\mu}g$ 얻을 수 있는 발현조건을 정립하였다. 또한 HtrA1 serine protease 활성은 protease의 농도와 substrate와의 반응시간에 dependent하며, substrate와의 반응온도가 $42^{\circ}C$일 때 최적의 serine protease활성을 나타내는 것을 알 수 있었다. 특히 $200{\mu}M$의 HtrA1 serine protease를 $37^{\circ}C$에서 3시간 반응 시켰을 때, substrate로 사용한 ${\beta}-casein$의 약 50%가 절단되는 것을 관찰하였다. 따라서 이 반응조건에 사용한 HtrA1의 양을 1 unit으로 하여 HtrA1의 serine protease활성을 여러 조건에서 비교 분석할 수 있다 본 연구에서 정립한 mature HtrA1을 다량으로 얻을 수 있는 발헌 및 정제조건과 serine protease 최적 활성조건은 HtrA1의 serine protease 활성과 생물학적 기능의 상관관계를 이해하는데 활용될 수 있을 것이다.