• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1474-1478
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• 2010

An efficient method for labeling individual proteins in live cells is required for investigations into biological mechanisms and cellular processes. Here we describe the preparation of small quantum dots (QDs) that target membrane surface proteins bearing a hexahistidine-tag ($His_6$-tag) via specific binding to an nitrilotriacetic acid complex of nickel(II) ($NTA{\cdot}Ni^{2+}$) on the QD surfaces. We showed that the $NTA{\cdot}Ni^{2+}$-QDs bound to His-tag functionalized beads as a cellular mimic with high specificity and that QDs successfully targeted $His_6$-tagged vesicle-associated membrane proteins (VMAP) on cell surfaces. This strategy provides an efficient approach to monitoring synaptic protein dynamics in spatially restricted and confined biological environments.

• Journal of Pharmaceutical Investigation
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• 제20권4호
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• pp.179-191
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• 1990

A central dogma of pharmacology is that only unbound drug is capable of translocation across biological membrane. Thus, hepatic uptake is assumed to be solely determined by the unbound concentration of the diffusible moiety at the surface of the liver cell. However, an increasing number of experimental observations with xenobiotics that are normally very extensively bound to plasma proteins (>99%) appear to be inconsistent with these assumptions. This suggested that in addition to progressive spontaneous dissociation within the liver sinusoids and space of Disse, direct interactions of the albumin-drug complex at the plasma membrane may facilitate dissociation of the complex. To explain this phenomena. called albumin-mediated uptake, 4 mechanisms have been suggested. The validity of such hypotheses needs to be examined by the further study. Because albumin-mediated uptake has also been observed to occur in other plasma proteins, protein-mediated uptake rather than albumin-mediated uptake seems to be acceptable.

• 동의생리병리학회지
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• 제25권1호
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• pp.29-36
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• 2011

Nardostachyts chinensis (N. chinensis) belonging to the family Valerianaceae has been used to elicit stomachic and sedative effects. The MAPKs are serine/threonine kinases involved in the regulation of various cellular responses, such as cell proliferation, differentiation and apoptosis. The PKC also plays a key role in regulating the response of hematopoietic cells to both physiological and pathological inducers of proliferation and differentiation. This study investigated the signaling pathways on the U937 cell differentiation induced by N. chinensis. N. chinensis induced the differentiation of U937 cells, as shown by increased of differentiation surface antigen CD11b. Activation of ERK increased time-dependently in differentiation of U937 cells induced by N. chinensis, but activations of JNK and p38 were unaffected. Inhibitor of ERK (PD98059) significantly reduced CD11b expression induced by N. chinensis in U937 cells. In addition, N. chinensis increased protein level of PKC ${\beta}$I and PKC ${\beta}$II isoforms, but the protein level of PKC ${\alpha}$ and PKC ${\gamma}$was constant. PKC inhibitors (GF 109203X and H-7) inhibited U937 cell differentiation and the ERK activation induced by N. chinensis. These results indicated that PKC and ERK may be involved in U937 cell differentiation induced by N. chinensis.

• The Korean Journal of Physiology and Pharmacology
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• 제4권6호
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• pp.507-513
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• 2000

ErbB3/HER3 is a cell surface receptor which belongs to the ErbB/HER subfamily of receptor protein tyrosine kinases. When expressed in NIH/3T3 cells, ErbB3 can form heterodimeric coreceptor with endogenous ErbB2. Among known intracellular effectors of the ErbB2/ErbB3 are mitogen-activated protein kinase (MAPK) and phosphoinositide (PI) 3-kinase. In the present study, we studied relative contributions of above two distinct signaling pathways to the heregulin-induced mitogenic response via activated ErbB3. For this, clonal NIH-3T3 cell lines expressing wild-type ErbB3 and ErbB3 mutants were stimulated with $heregulin{\beta}_1$. While cyclin D1 level was markedly high and further increased by treatment of heregulin in cells expressing wild-type ErbB3, the elimination of either Shc binding or PI 3-kinase binding lowered both levels. This result was supported by the reduction of cyclin $D_1$ expression by preteatment with MAPK kinase inhibitor or PI 3-kinase inhibitor before stimulation with heregulin. In accordance with the cyclin $D_1$ expression, elimination of either Shc binding or PI 3-kinase binding reduced the heregulin-induced DNA synthesis and cell growth rate. Our results obtained by the comparison of wild-type and ErbB3 mutants indicate that the full induction of the cell cycle progression through $G_1/S$ phase by ErbB3 activation is dependent on both Shc/MAPK and PI 3-kinase signal transduction pathways.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.143-152
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• 2001

Korean-style fermented soybean paste (KFSP), Doenjang, is a traditional food that is consumed as a protein source in Korea. Recently, efforts to identify biolgocial response modifiers (BRMs) have been focused on food products. Accordingly, this study which isolated abiologically active substance form KFSP, named KFSP-BRM, ws defined to be aheat-stable carbohydrate with a molecular weight of 2,000 kDa. The biological activity of KFSP-BRM was not inactivated by treatment with an anti-LPS antibody. The oral as well as intraperitoneal treatment of mice with KFSP-BRM significantly enhanced the number of B cells expressing surface significantly enhanced the number of B cells expressing surface immunoglobulins (IgM and IgG). Subsequently, an increased level of immunoglobulins in the sera was also observed. In vitro. KFSP-BRM was found to upregulate the production of interleukin-1 (IL-1) and IL-6 by mactro phages and B cells but not the production of IL-2 by T cells. In conclusion, these data demonstrate the presence of a BRM in KFSP, which may provide an additional benefit to those consuming it is a food. KFSP-BRM is a novel B cellmitogen distinct from fresh soybean lectin or B cell mitogens, such as LPS and Streptococcus protein A. The major biological effects of KFSP-BRM would appear to be anincreased production of IL-1 and IL-6 by macrophages and B cells, thereby enhancing the function of mature B cells.

• 생명과학회지
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• 제34권4호
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• pp.279-285
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• 2024

Zonula occludens (ZO) 단백질은 세포 간의 접합 및 세포질 표면에서 구조적으로 기초를 제공하는 스캐폴딩 단백질로 통합 막 단백질과 세포골격 사이를 연결해주는 역할을 하며 구조적 기능 이외에도 세포 성장 및 증식 조절에도 참여를 한다. 최근 연구들에 따르면 ZO 단백질이 여러 질병 중에서도 암에 관여를 한다는 사실을 보여주고 있다. 특히, ZO 단백질은 암 미세환경에서 암세포의 성장과 발달에 영향을 주고 있다고 보고되고 있다. ZO 단백질은 혈관신생, 염증 반응, 상피-중간엽 전이, 중간엽 줄기 세포와의 상호작용을 통해 암 미세환경에서 다양한 기능을 수행한다. 이런 작용 메커니즘은 암의 종류 및 환경적 조건에 따라 달라질 수 있어 최근까지도 이와 관련된 연구들이 진행되면서 ZO 단백질이 참여하는 여러 신호전달기작들이 밝혀지고 있다. 이를 통해 암세포 환경에서 암 성장과 발달을 늦춰줄 수 있는 새로운 치료법도 고려해 볼 수 있다. 또한 ZO 단백질의 세포 및 생체 내 역할에 대한 연구는 계속되고 있지만, 신호전달 기작들이 생체 내 암 미세환경에서 어떻게 작용하는지에 대한 이해는 아직 부족하다. 따라서, 본 리뷰에서는 ZO 단백질 관련 암 미세환경의 특징 및 조절 기작을 소개하고 ZO 단백질의 특성을 활용하여 암 세포 환경을 억제하고 생체 내 ZO 단백질의 역할을 고찰하고자 한다.

• 한국미생물·생명공학회지
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• 제37권4호
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• pp.355-360
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• 2009

P. carageenovora 유래 arylsulfatase 유전자(astA)의 효모표면발현 plasmid pCTAST(7.1 kb)를 구축하여 S. cerevisiae EBY100에 형질전환하였고, 선별된 형질전환체들을 YPDG 배지에서 배양했을 때 4-methylumbelliferyl sulfate를 분해하여 형광을 보였다. 이는 효모에서 arylsulfatase가 활성형으로 생산되었음을 의미하였다. S. cerevisiae EBY100/pCTAST를 플라스크 배양했을 때 arylsulfatase 활성은 galactose가 완전히 소모된 배양 48시간째 최대 활성인 1.2 unit/mL로 나타났으며 배양 상등액에서는 활성이 나타나지 않았다. 효모 S. cerevisiae의 세포표면에서 발현된 재조합 arylsulfatase로 제조된 agarose를 agar와 시판용 agarose와 함께 ${\lambda}DNA$ HindIII marker를 사용하여 DNA 전기영동 성능을 비교 실험한 결과, agar보다는 재조합 arylsulfatase 처리로 제조한 agarose가 이동성이나 분리능에서 우수하였으며, 시판용 agarose와 비교하여 이동성이나 분리능이 유사한 결과를 확인할 수 있었다. 본 연구의 결과, 효모 S. cerevisiae의 세포표면에서 발현된 재조합 arylsulfatase 효소를 이용하여 한천으로부터 전기영동용 고순도 친환경적인 agarose 생물 생산 공정에 적용 가능함을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제17권6호
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• pp.525-530
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• 2013

Multidrug resistance 3 (MDR3) is expressed on the canalicular membrane of the hepatocytes and plays an important role in protecting the liver from bile acids. Altered ABCB4 gene expression can lead to a rare hepatic disease, low phospholipid-associated cholelithiasis (LPAC). In this study, we characterized 3 ABCB4 mutations in LPAC patients using various in vitro assay systems. We first measured the ability of each mutant to transport paclitaxel and then the mechanisms by which these mutations might change MDR3 transport activity were determined using immunoblotting, cell surface protein biotinylation, and immunofluorescence. Through a membrane vesicular transport assay, we observed that the uptake of paclitaxel was significantly reduced in membrane vesicles expressing 2 ABCB4 mutations, F165I and S320F. Both mutants showed significantly decreased total and cell surface MDR3 expression. These data suggest two missense mutations of ABCB4 may alter function of MDR3 and ultimately can be determined as LPAC-causing mutations.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.823-828
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• 2000

The complete nucleotide sequence of hepatitis B virus DNA isolated from Korean patient serum was determined and characterized, and its phylogenetic relation was then investigated. The viral genome was 3,215 base pairs long and included four well known open reading frames (i.e. surface antigens, core antigens, X protein and DNA polymerase). The sequence of the surface antigen showed that the HBV genome under investigation, designated HBV 315, was characteristic of subtype adr. A phylogenetic analysis using the total genome sequence revealed that HBV315 was grouped into genomic group C together with isolates from Japan, China, Thailand, Polynesia, and New Caledonia. The mean percent similarity between HBV315 and other HBV isolates in genomic group C was 97.25%, and that with other genomic groups ranged from 86.16% to 91.25%. The predicted amino acid sequences of HBV315 were compared with two closely related subtype adr isolates, M38636 and D12980. The results showed that the X gene product was identical in the three strains, while there were significant amino acid sequence differences between HBV315 and M38636 in the Pre-S1 and Pre-S2 regions.

• 대한한의학회지
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• 제27권2호
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• pp.182-195
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• 2006

Objectives : We examined the effect of Hwangryunhaedoktang(HH) on the experimental ulcerative colitis induced by dextran sulfate sodium (DSS). Methods : Experimental colitis was induced in rats by daily treatment with 5% DSS in the drinking water for 5 days. Afterward, the mts were divided into two groups: the control group was administered water and the sample group was administered HH for 7 days. Results : The sample group provided HH for 7 days demonstrated fast recovery of body weight compared with the control group. Histologic change showed fast regeneration of crypt and surface epithelial cells and decreased edema of the submucosa and decreased lymphatic follicle of mucosa compared with the control group. Immunohistochemical stain usingCOX-2 gene was decreased and there was localized Ki-67 positive reaction. Regeneration of surface epithelial cell and goblet cell in mucosa was observed by transmission electron microscope. These results indicate therapeutic effect of HH on DSS-induced colitis in rats.