• 제목/요약/키워드: cell surface protein

검색결과 461건 처리시간 0.024초

Preparation of Diphtheria Toxin A Chain from Escherichia coli

  • Lee, Jong-Soo;Yoon, Kyoung-Bum;Park, Jong-Won;Choi, Suk-Jung
    • BMB Reports
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    • 제30권2호
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    • pp.144-149
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    • 1997
  • An expression vector was constructed containing the gene encoding diphtheria toxin A (DTA) which was placed after a T7 promoter. Cytoplasmic expression of the DTA gene resulted in the formation of an insoluble inclusion body. The inclusion body was collected after the complete lysis of the cell, and subsequent washing with 0.1% Triton X-100 released 16~30% of DTA protein from the inclusion body along with other contaminating proteins. The released DTA protein was purified by dialysis. The remaining pellet was dissolved in 8 M urea containing 5% ${\beta}-mercaptoethanol$, and the denatured DTA was renatured by the dilution-dialysis method. The total yield was 35%, and about 5 mg DTA was obtained from 1 L culture. The DTA protein has a free sulfhydryl group exposed to the protein surface, and was shown to have a tendency to dimerize through disulfide formation in the absence of ${\beta}-mercaptoethanol$. The utility of the sulfhydryl group was tested for the construction of recombinant toxins.

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Possible target for G protein antagonist: Identification of specific amino acid residue responsible for the molecular interaction of G$\alpha$ 16 with chemoattractant C5a receptor.

  • 이창호
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2000년도 춘계학술대회
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    • pp.17-19
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    • 2000
  • Heterotrimeric G Proteins transduce ligand binding to a wide variety of seven transmembrane cell surface receptors into intracellular signals. The currently accepted model for the activation of G protein suggests that ligand-activated receptor accelerates GDP-GTP exchange reactions on the ${\alpha}$ subunit of the heterotrimeric G protein. At least seventeen distinct isoforms of the G${\alpha}$ subunit protein have been identified in mammalian organisms. Among them, the G${\alpha}$q family consists of five members whose ${\alpha}$ subunits show different expression patterns. G${\alpha}$q and G${\alpha}$11 seem to be almost ubiquitously expressed, whereas G${\alpha}$14 is predominantly expressed in spleen, lung, kidney and testis. G${\alpha}$16 and its murine counterpart G${\alpha}$15 are expressed in hematopoietic cells and has been shown to couple a wide variety of receptors to phosphoinositide-specific phospholipase C activity. Beta-isoforms of phospholipase C were shown to be activated by all members of G${\alpha}$q family, i.e., G${\alpha}$q, G${\alpha}$11, G${\alpha}$l4 and G${\alpha}$16 subunits either in reconstitution system. or in experiments using cDNA transfection with intact Cos-7 cells.

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Isolation of Differentially Expressed Genes in Chondrocytes Treated with Methylprednisolone by Subtractive Hybridization

  • Kim, Ji-Hee;Kang, Soon-Min;Suh, Jin-Soo;Kim, Chong-Rak
    • 대한의생명과학회지
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    • 제8권3호
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    • pp.195-202
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    • 2002
  • Osteoarthritis (OA), the most common form of arthritis, involves the destabilization of the normal balance between the degradation and the synthesis of articular cartilage and subchondral bone within a joint. As articular cartilage degrades over time, its smooth surface roughens and bone-against-bone contact ensues, producing the inflammation response symptomatic of this 'wear and tear' disease. Although a variety of genetic, developmental, metabolic, and traumatic factors may initiate the development of osteoarthritis, its symptoms (joint pain, stiffness, and curtailed function) typically evolve slowly, and patients experience periods of relative calm alternation with episodes of inflammation and pain. Rheumatoid arthritis (RA), an autoimmune disease of unknown etiology characterized by chronic synovitis and cartilage destruction, affect 1% of the total population. Cartilage is a specialized connective tissue in which the chondrocytes occupy only 5% of the volume. Cartilage is particularly rich in extracellular matrix, with matrix making up 90% of the dry weight of the tissue chondrocytes have cell processes that extend a short distance into the matrix, but do not touch other cells thus in cartilage, cell-matrix interactions are essential for the maintenance of the extracellular matrix. In this study, subtractive hybridization method was utilized to detect genes differentially expressed in chondrocytes treated with methylprednisolone. We have isolated 57 genes that expressed differentially in the chondreocytes by methylprednisolone. 13 clones of them were analyzed with sequencing and their homologies were searched. 8 cDNAS included KIAA 0368, upregulated during skeletal muscle growth 5 (usmg 5), ribosomal protein S 18 (RPS 18), skeletal muscle ryanodine receptor, radial spoke protein 3 (RSP 3), ribosomal protein QM, ribosomal protein L37a (RPL37A), cytochrome coxidase subunit VIII (COX8).

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Chemotactic Effect of Leukotactin-1/CCL15 on Human Neutrophils

  • Lee Ji-Sook;Yang Eun-Ju;Ryang Yong-Suk;Kim In-Sik
    • 대한의생명과학회지
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    • 제12권3호
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    • pp.145-151
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    • 2006
  • Leukotactin-l (Lkn-l )/CCL15 has been known as a potent chemoattractant of leukocytes. However, the precise function of Lkn-l in human neutrophils has not been explained well. In the present study, we investigated the contribution of Lkn-1 in chemotactic activity of human neutrophils. Both CCR1 and CCR3 mRNA expressions are strongly expressed in human neutrophils but CCR2 protein expression was uniquely detected on the cell surface. Lkn-l binding to CCR1 and CCR3 induced chemotactic activity of neutrophils. Chemotactic index of Lkn-l was comparable to that of IL-8. $MIP-1{\alpha}/CCL3$ binding to CCR1 and CCR5 has no effect on neutrophil migration. Cell migration, in response to Lkn-l, was blocked by pertussis toxin (Ptx), a $G_o/G_i$ protein inhibitor, and U73122, a phospholipase C(PLC) inhibitor but not by protein kinase C inhibitor such as rottlerin, and Ro-31-8425. Taken together, our results demonstrate that Lkn-l transduces the chemotaxis signal through $G_o/G_i$ protein and PLC. This finding provides the molecular mechanism by which Lkn-l may contribute to neutrophil movement into the site of inflammation.

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Rosmarinic Acid Down-Regulates the LPS-Induced Production of Monocyte Chemoattractant Protein-1 (MCP-1) and Macrophage Inflammatory Protein-1α (MIP-1α) via the MAPK Pathway in Bone-Marrow Derived Dendritic Cells

  • Kim, Hyung Keun;Lee, Jae Joon;Lee, Jun Sik;Park, Yeong-Min;Yoon, Taek Rim
    • Molecules and Cells
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    • 제26권6호
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    • pp.583-589
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    • 2008
  • In the present study, we investigated whether rosmarinic acid, which has been suggested to exhibit anti-inflammatory properties, can suppress the expressions of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-$1{\alpha}$ ($MIP-1{\alpha}$) via the MAPK pathway in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) in the presence of GM-CSF and IL-4 in media. The effects of rosmarinic acid were investigated in BMDCs with respect to the following; cytotoxicity, surface molecule expression, dextran-FITC uptake, cell migration, chemokine gene expression, and the MAPK signaling pathway. Rosmarinic acid was found to significantly inhibit the expressions of CD80, CD86, MHC class I, and MHC class II in LPS-stimulated mature BMDCs, and rosmarinic acid-treated BMDCs were found to be highly efficient with regards to antigen capture via mannose receptor-mediated endocytosis. In addition, rosmarinic acid reduced cell migration by inducing the expression of a specific chemokine receptor on LPS-induced mature BMDCs. Rosmarinic acid also significantly reduced the expressions of MCP-1 and $MIP-1{\alpha}$ induced by LPS in BMDCs and inhibited LPS-induced activation of MAPK and the nuclear translocation of $NF-{\kappa}B$. These findings broaden current perspectives concerning our understanding of the immunopharmacological functions of rosmarinic acid, and have ramifications that concern the development of therapeutic drugs for the treatment of DC-related acute and chronic diseases.

Inhibitory effects of oroxylin A on endothelial protein C receptor shedding in vitro and in vivo

  • Ku, Sae-Kwang;Han, Min-Su;Lee, Min Young;Lee, You-Mie;Bae, Jong-Sup
    • BMB Reports
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    • 제47권6호
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    • pp.336-341
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    • 2014
  • Endothelial cell protein C receptor (EPCR) plays important roles in blood coagulation and inflammation. EPCR activity is markedly changed by ectodomain cleavage and release as the soluble EPCR. EPCR can be shed from the cell surface, which is mediated by tumor necrosis factor-${\alpha}$ converting enzyme (TACE). Oroxylin A (OroA), a major component of Scutellaria baicalensis Georgi, is known to exhibit anti-angiogenic, antiinflammation, and anti-invasive activities. However, little is known about the effects of OroA on EPCR shedding. Data showed that OroA induced potent inhibition of phorbol-12-myristate 13-acetate (PMA), tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$ and on cecal ligation and puncture (CLP)-induced EPCR shedding through suppression of TACE expression and activity. In addition, treatment with OroA resulted in reduced PMA-stimulated phosphorylation of p38, extracellular regulated kinases (ERK) 1/2, and c-Jun N-terminal kinase (JNK). These results demonstrate the potential of OroA as an anti-sEPCR shedding reagent against PMA and CLP-mediated EPCR shedding.

임파구 ADP-ribosyltransferase의 rat mammary adenocarcinoma cell에서의 발현 (Expression of Lymphocyte ADP-ribosyltransferase in Rat Mammary Adenocarcinoma Cells)

  • 김현주
    • 생명과학회지
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    • 제8권1호
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    • pp.102-108
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    • 1998
  • Gltcosylphosphatidylinositol (GPI)에 의해 고정된 단백질의 초기 형태는 골지체에서의 직접적인 processing을 수행하기 위한 아미노와 카르 복시 말단의 hydrophobic signal sequence를 소유하고 있다. 앞서, mouse 임파구로부터 NAD;arginine ADP-ribosyltransferase (Yac-1)가 클로닝되었으며 Yac-1 transferase의 아미노산 배열을 추정해 본 결과, hydrophobic 아미노와 카르복시 말단을 포함하고 있었으며 이는 GPI-anchroed 단백질들의 알려진 signal sequence와 일치하였다. 미 transferase는 야생형의 cDNA로 transfection된 NMU (rat mammary adenocarcinoma) cell의 표면에 존재하였으며 phosphoatidylinosotol-specific phospholipase C에 의해 방출되어졌다. 카르복시 말단의 hydrophobic sequence가 없는 돌연변이체는 수용성이며 분비성인 transferase를 생산하였다. 이러한 사실은 카르복시 말단의 sequence가 없는 돌연변이체는 수용성이며 분비성인 transferase를 생산하였다. 이러한 사실은 카르복시 말단의 sequence가 GPI의 부착에 중요함을 나타내준다.

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Acceleration of Wound Healing on Scald Burn Skin Using Irradiation of TDP and Skin Spread of Myrrha

  • Cho Hyun Gug;Kim Keum-Suk;Lee Jong-wook
    • 대한의생명과학회지
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    • 제11권2호
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    • pp.243-248
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    • 2005
  • The present study was conducted to determine whether skin spread of Myrrha and Tending Diancibo Pu (TDP) irradiation have a remarkable effect on the cell regeneration as well as wound healing following dermal scald burn injury. Burn injury was induced on dorsal surface $(TBSA\;15\~20\%)$ by scald burn in rats. Postburn concentration of serum protein was significantly decreased compared with sham-treated, double treatment with Myrrha and TDP was significantly increased the protein concentration compared with that of burn control. The content of keratinocyte growth factor (KGF) at 48 h is higher than that of at 24 h, and double treatment with Myrrha and TDP was the most effective to increase the production of KGF in all experimental groups. Morphologically, epithelial regeneration and dermal collagen synthesis by fibroblasts were accelerated in Myrrha and TDP treated group compared with bum control at same time postburn. At 48 h after burn, all dermal connective tissues are recovered to new collagen fibers in case of Myrrha and TDP double treated group. The data suggest that double treatment with skin spread of Myrrha and TDP radiation have a remarkable effect of to accelerate cell regeneration and wound healing in case of scald burn skin.

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The Pleiotropic Face of CREB Family Transcription Factors

  • Md. Arifur Rahman Chowdhury;Jungeun An;Sangyun Jeong
    • Molecules and Cells
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    • 제46권7호
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    • pp.399-413
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    • 2023
  • cAMP responsive element-binding protein (CREB) is one of the most intensively studied phosphorylation-dependent transcription factors that provide evolutionarily conserved mechanisms of differential gene expression in vertebrates and invertebrates. Many cellular protein kinases that function downstream of distinct cell surface receptors are responsible for the activation of CREB. Upon functional dimerization of the activated CREB to cis-acting cAMP responsive elements within the promoters of target genes, it facilitates signal-dependent gene expression. From the discovery of CREB, which is ubiquitously expressed, it has been proven to be involved in a variety of cellular processes that include cell proliferation, adaptation, survival, differentiation, and physiology, through the control of target gene expression. In this review, we highlight the essential roles of CREB proteins in the nervous system, the immune system, cancer development, hepatic physiology, and cardiovascular function and further discuss a wide range of CREB-associated diseases and molecular mechanisms underlying the pathogenesis of these diseases.

바이오접합과 자가결합을 이용한 박테리아 세포막의 위치 특이적 형광 표지 (Site-specific Dye-labeling of the Bacterial Cell Surface by Bioconjugation and Self-assembly)

  • 양이지;임성인
    • Korean Chemical Engineering Research
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    • 제60권3호
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    • pp.398-406
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    • 2022
  • 그람음성균의 외막은 수많은 생물물리학적 및 생화학적 과정이 작용하여 생존력을 유지하도록 설계되어 있는 세포환경의 가장 바깥 층이다. 세포공학의 발전으로 인해 박테리아의 막 환경을 변경하는 등 유전정보를 원하는 대로 조작할 수 있게 되었고 이는 박테리아를 특정 목적에 적용시킬 수 있게 하였다. 그중 기능성 분자를 박테리아 외막에 표지하는 세포 표면공학은 숙주세포가 특정 외부물질이나 자극에 반응하도록 유도하는 전략 중 하나이다. 기능성 펩타이드 또는 단백질을 세포 표면에 표지하기 위한 방법으로 막 고정 모티프를 융합한 후 세포 내에서 발현하는 방법이 일반적으로 사용되고 있지만 이는 박테리아 시스템에서 발현할 수 없는 외인성 단백질이나 크기가 큰 단백질에는 적용할 수 없다는 한계점이 있다. 박테리아 외막의 구성요소에 자연적으로 존재하는 반응성 그룹과 기능성 물질을 화학접합하는 방법도 있으나 필수 구성 요소의 비특이적 변형으로 인해 세포의 생장이 저해되는 경우가 많다. 본 연구에서는 비천연아미노산 또는 자가결합 도메인을 사용해 대장균의 세포 표면을 부위 특이적으로 형광 표지하는 두 가지의 접근법을 수행하였다. 첫 번째 접근법은 화학선택적 반응성을 지닌 비천연아미노산이 삽입된 펩타이드를 대장균 표면에 발현하여 위치 특이적으로 형광염료를 접합시키는 방법이다. 두 번째 접근법은 자가결합능력을 지닌 이종 이량체 코일-코일에서 유래된 α-나선 도메인을 대장균 외막에 발현하고 녹색 형광 단백질이 융합된 상보적인 α-나선 도메인을 막 표면에 특이적으로 고정하는 방법이다. 제시된 방법들은 위치와 시간이 제어된 방식으로 박테리아 외막에 새로운 기능을 부여하는 방법론으로서 유용하다.