• 한국미생물·생명공학회지
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• 제37권2호
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• pp.91-98
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• 2009

김치 소비가 증가하면서 공장에서 큰 규모로 만들어지게 되었다. 그래서 상업용 김치의 위생 상태는 주 관심사가 되었다. 충분히 발효되지 않은 상업용 김치로부터 17종의 대장균유사세균(coliform bacteria)을 분리하였다. 16S rDNA 분석에 의하여 Enterobacter intermedius, Ent. cloacae, Ent. amnigenus, Klebsiella terrigena, K. ornithinolytica, K. oxytoca, Hafnia alvei 등의 3속 7종으로 부분 동정되었다. 한편, 오래된 배추김치로부터 Lactobacillus paraplantarum KNUC25라고 부분 동정된 젖산균이 분리되어 그의 항미생물 활성이 보고되었다. 이 균주는 spot-on the lawn test와 세포생존실험을 통하여 본 연구에서 분리한 대장균유사세균과 몇몇 유해한 대장균유사세균에 대하여 항세균 활성을 보여 주었다. 상업용 김치에 있는 대장균유사세균은 L. paraplantarum KNUC25균주 배양 상층액의 첨가에 의하여 효과적으로 억제되었다.

• 생명과학회지
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• 제25권9호
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• pp.1000-1006
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• 2015

α-Asarone은 동양의 전통적인 약재로 잘 알려진 석창포(Acorus gramineus)의 주된 성분이다. 석창포는 항위궤양, 항알러지, 히스타민 방출 억제 그리고 항산화 효과와 같이 다양한 효과를 나타내는 것으로 잘 알려져 있다. 그러나 석창포 역할에 대한 기전연구는 아직 부족한 실정이다. 본 연구에서는, HT1080 세포주에서 α-asarone의 항산화 효과뿐만 아니라 matrix metalloproteinase에 대한 효과를 조사하였다. 가장 먼저 α-asarone의 세포 생존에 대한 효과를 조사하기 위해 MTT assay를 이용하여 16 μM이하에서 세포독성이 없음을 나타내었다. α-asarone이 환원력과 fenton reaction에 의해 유도된 DNA 산화로부터 보호효과를 나타내는 것을 확인하였다. 더욱이, α- asarone은 collagenase 활성을 증가시키고 phorbol 12-myristate 13-acetate (PMA)로 자극된 MMP-2 및 MMP-9의 활성을 증가시켰다. 한편 phenazine methosulfate (PMS) 로 자극된 경우 MMP-9의 활성은 α-asarone의 존재하에서 증가되었으나 MMP-2 활성에는 변화가 없었다. 그러므로 우리의 연구결과는 α-asarone이 산화적 스트레스 및 MMPs와 관련된 병리학적 질환의 예방 및 치료제로 개발이 기대된다고 제안한다.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1881-1890
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• 2016

Manganese superoxide dismutase (MnSOD) is a vital enzyme that protects cells from free radicals through eliminating superoxide radicals ($O^{2-}$). Hirudin, a kind of small active peptide molecule, is one of the strongest anticoagulants that can effectively cure thrombus diseases. In this study, we fused Hirudin to the C terminus of human MnSOD with the GGGGS linker to generate a novel dual-feature fusion protein, denoted as hMnSOD-Hirudin. The hMnSOD-Hirudin gene fragment was cloned into the pET15b (SmaI, CIAP) vector, forming a recombinant pET15b-hMnSOD-Hirudin plasmid, and then was transferred into Escherichia coli strain Rosetta-gami for expression. SDS-PAGE was used to detect the fusion protein, which was expected to be about 30 kDa upon IPTG induction. Furthermore, the hMnSOD-Hirudin protein was heavily detected as a soluble form in the supernatant. The purification rate observed after Ni NTA affinity chromatography was above 95%. The hMnSOD-Hirudin protein yield reached 67.25 mg per liter of bacterial culture. The identity of the purified protein was confirmed by western blotting. The hMnSOD-Hirudin protein activity assay evinced that the antioxidation activity of the hMnSOD-Hirudin protein obtained was $2,444.0{\pm}96.0U/mg$, and the anticoagulant activity of the hMnSOD-Hirudin protein was $599.0{\pm}35.0ATU/mg$. In addition, in vitro bioactivity assay showed that the hMnSOD-Hirudin protein had no or little cytotoxicity in H9c2, HK-2, and H9 (human $CD_4{^+}$, T cell) cell lines. Transwell migration assay and invasion assay showed that the hMnSOD-Hirudin protein could suppress human lung cancer 95-D cell metastasis and invasion in vitro.

• 한국영양학회:학술대회논문집
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• 한국영양학회 1995년도 추계학술대회 초록
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• pp.11-34
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• 1995

Growth hormone (GH) plays a key role in regulating postnatal growth and can stimulate growth of animals by acting directly on specific receptors on the plasma membrane of tissues or indirectly through stimulating insulin-like growth factor (IGF)-I synthesis and secretion by the liver and other tissues. IGF-I and IGF-Ⅱ are polypeptides with structural similarity with proinsulin that stimulate cell proliferation by endocrine, paracrine and autocrine mechanisms. The initial event in the metabolic action of IGFs on target cells appears to be their binding to specific receptors on the plasma membrane. Current evidence indicates that the mitogenic actions of both IGFs are mediated primarily by binding to the type I IGF receptors, and that IGF action is also mediated by interactions with IGF-binding proteins (IGFBPs). Six distinct IGFBPs have been identified that are characterized by cell-specific interaction, transcriptional and post-translational regulation by many different effectors, and the ability to either potentiate or inhibit IGF actions. Nutritional deficiencies can have their devastating consequence during growth. Although IGF-I is the major mediator of GH's action on somatic growth, nutritional status of an organism is a critical regulator of IGF-I and IGFBPs. Various nutrient deficiencies result in decreased serum IGF-I levels and altered IGFBP levels, but the blood levels of GH are generally unchanged or elevated in malnutrition. Effects of protein, energy, vitamin C and D, and zinc on serum IGF and IGFBP levels and tissue mRNA levels were reviewed in the text. Multiple factors are involved in the regulation of intestinal epithelial cell growth and differentiation. Among these factors the nutritional status of individuals is the most important. The intestinal epithelium is an important site for mitogenic action of the IGFs in vivo, with exogenous IGF-I stimulating mucosal hyperplasia. Therefore, the IGF system appears to provide and important mechanism linking nutrition and the proliferation of intestinal epithelial cells. In order to study the detailed mechanisms by which intestinal mucosa is regulated, we have utilized IEC-6 cells, an intestinal epithelial cell line and Caco-2 cells, a human colon adenocarcinoma cell line. Like intestinal crypt cells analyzed in vivo or freshly isolated intestinal epithelial cells, IEC-6 cells and Caco-2 cells possess abundant quatities of both type Ⅰ and type Ⅱ IGF receptors. Exogenous IGFs stimulate, whereas addition of IGFBP-2 inhibits IEC-6 cell proliferation. To investigate whether endogenously secreted IGFBP-2 inhibit proliferation, IEC-6 cells were transfected with a full-length rat IGFBP-2 cDNA anti-sense expression construct. IEC-6 cells transfected with anti-sense IGFBP-2 protein in medium. These cells grew at a rate faster than the control cells indicating that endogenous IGFBP-2 inhibits proliferation of IEC-6 cells, probably by sequestering IGFs. IEC-6 cells express many characteristics of enterocyte, but do not undergo differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation after reaching confluency. We have demonstrated that Caco-2 cells produce IGF-Ⅱ, IGFBP-2, IGFBP-3, and an as yet unidentified 31,000 Mr IGFBP, and that both mRNA and peptide secretion of IGFBP-2 and IGFBP-3 increased, but IGFBP-4 mRNA and protein secretion decreased after the cells reached confluency. These changes occurred in parallel to and were coincident with differentiation of the cells, as measured by expression of sucrase-isomaltase. In addition, Caco-2 cell clones forced to overexpress IGFBP-4 by transfection with a rat IGFBP-4 cDNA construct exhibited a significantly slower growth rate under serum-free conditions and had increased expression of sucrase-isomaltase compared with vector control cells. These results indicate that IGFBP-4 inhibits proliferation and stimulates differentiation of Caco-2 cells, probably by inhibiting the mitogenic actions of IGFs.

• 한국자원식물학회지
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• 제26권2호
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• pp.149-158
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• 2013

본 연구에서는 지유 에탄올추출물의 항산화 효과를 조사하였다. Pyrogallol의 억제율을 100%로 기준하였을 때, DPPH 라디칼을 50% 억제시키는데 필요한 지유 추출물의 농도는 0.33 mg/mL으로 ${\alpha}$-tocopherol의 $IC_{50}$(0.40 mg/mL)과 유사하게 나타났다. 지유 추출물의 총항산화능은 ${\alpha}$-tocopherol에 비해 높게 나타났다. 지유 추출물의 superoxide 소거활성은 catechin에 비해 높게 나타났다. 지유 추출물의 peroxyl 라디칼 소거활성은 ascorbic acid에 비해 높게 나타났다. 지유 추출물의 구리이온 환원력은 ${\alpha}$-tocopherol에 비해 높게 나타났다. 지유 추출물은 hydroxyl 라디칼 및 peroxyl 라디칼로 유발된 supercoiled DNA strand의 절단을 억제시켰다. 지유 추출물 0.5 및 5 mg/mL의 총페놀 함량은 각각 0.50 및 3.33 mM gallic acid와 동등한 수준이었다. 또한, HepG2 세포주를 이용한 세포배양에서 지유 추출물 0.01, 0.1 및 0.5 mg/mL 농도의 첨가는 0.2 mM t-BHP로 유도된 세포독성을 각각 33.8, 79.1 및 96.9% 감소시켰다. 따라서, 본 연구 결과들은 지유 추출물의 강력한 항산화 효과와 세포독성 억제효과를 나타내며, 이러한 효능은 적어도 자유라디칼의 산화억제와 높은 총페놀 함량에 기인하는 것으로 사료된다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 International Meeting 2000
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• pp.23-36
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• 2000

Japanese encephalitis virus (JEV) is the causative agent of a mosquito-borne encephalitis and is transmitted to human via persistently infected mosquito vectors. Although the virus is known to cause only acute infection, there were reports that showed neurological sequelae, latent infection in peripheral mononuclear cells, and recurrence of the disease after acute encephalitis. Innate resistance of certain cell lines, abnormal SN1 expression of the virus, and anti-apoptotic effect of cullular bcl-2 have been suggested as probable causes of JEV persistence even in the absence of defective interfering (DI) particles. Although possible involvement of DI particles in JEV persistence was suggested, neither has a direct evidence for DI presence nor its molecular characterization been made. Two questions asked in this study are whether the DI virus plays any role in JEV persistent infection if it is associated with and what type of change(s) can be made in persistently infected cells to avoid apoptosis even with the continuous virus replication, DI-free standard stock of JEV was infected in BHK-21, Vero, and SW13 cells and serial high multiplicity passages were performed in order to generate DI particles. There different-sized DI RNA species which were defective in both structural and nonstructural protein coding genes. Rescued ORFs of the DI genome maintained in-frame and the presence of replicative intermediate or replicative form RNA of the DI particles confirmed their replication competence. On the other hand, several clones with JEV persistent infection were established from the cells survived acute infections during the passages. Timing of the DI virus generation during the passages seemed coincide to the appearance of persistently infected cells. The DI RNAs were identified in most of persistently infected cells and were observed throughout the cell maintenance. One of the cloned cell line maintained the viral persistence without DI RNA coreplication. The cells with viral persistence released the reduced but continuous infectious JEV particle for up to 9 months and were refractory to homologous virus superinfection but not to heterologous challenges. Unlike the cells with acute infection these cells were devoid of characteristic DNA fragmentation and JEV-induced apoptosis with or without homologous superinfection. Therefore, the DI RNA generated during JEV undiluted serial passage on mammalian cells was shown to be biologically active and it seemed to be responsible, at least in part, for the establishment and maintenance of the JEV persistence in mammalian cells. Viral persistence without DI RNA coreplication, as in one of the cell clones, supports that JEV persistent infection could be maintained with or without the presence of DI particles. In addition, the fact that the cells with JEV persistence were resistant against homologous virus superinfection, but not against heterologous one, suggests that different viruses have their own and independent pathway for cytopathogenesis even if viral cytopathic effect could be converged to an apoptosis after all.

• International Journal of Oral Biology
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• 제34권1호
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• pp.7-14
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• 2009

Nitric oxide (NO) acts as an intracellular messenger at the physiological level but can be cytotoxic at high concentrations. The cells within periodontal tissues, such as gingival and periodontal fibroblasts, contain nitric oxide syntheses and produce high concentrations of NO when exposed to bacterial lipopolysaccharides and cytokines. However, the cellular mechanisms underlying NO-induced cytotoxicity in periodontal tissues are unclear at present. In our current study, we examined the NO-induced cytotoxic mechanisms in human gingival fibroblasts (HGF). Cell viability and the levels of reactive oxygen species (ROS) were determined using a MTT assay and a fluorescent spectrometer, respectively. The morphological changes in the cells were examined by Diff-Quick staining. Expression of the Bcl-2 family and Fas was determined by RT-PCR or western blotting. The activity of caspase-3, -8 and -9 was assessed using a spectrophotometer. Sodium nitroprusside (SNP), a NO donor, decreased the cell viability of the HGF cells in a dose- and time-dependent manner. SNP enhanced the production of ROS, which was ameliorated by NAC, a free radical scavenger. ODQ, a soluble guanylate cyclase inhibitor, did not block the SNP-induced decrease in cell viability. SNP also caused apoptotic morphological changes, including cell shrinkage, chromatin condensation, and DNA fragmentation. The expression of Bax, a member of the proapoptotic Bcl-2 family, was upregulated in the SNP-treated HGF cells, whereas the expression of Bcl-2, a member of the anti-apoptotic Bcl-2 family, was downregulated. SNP augmented the release of cytochrome c from the mitochondria into the cytosol and enhanced the activity of caspase-8, -9, and -3. SNP also upregulated Fas, a component of the death receptor assembly. These results suggest that NO induces apoptosis in human gingival fibroblast via ROS and the Bcl-2 family through both mitochondrial- and death receptor-mediated pathways. Our data also indicate that the cyclic GMP pathway is not involved in NO-induced apoptosis.

• 한국식품영양과학회지
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• 제25권4호
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• pp.551-559
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• 1996

10% sodium alginate와 cellulose의 장기간 섭취가 휜쥐(Sprague-Dawley, 수켯)의 소화생리에 미치는 영향은 다음과 같았다. 체중 증가량은 무섬유식이군과 cellulose군에 비해 sodium alginate군에서 유의적으로 낮았다(p<0.05). 소장의 무게와 길이 및 단위길이 당 무게는 무섬유식이군과 cellulose군에 비해 sodium alginate군에서 유의적으로 높았다(p<0.05). 분변의 부피 및 무게는 무섬유식이군에 비해 식이섬유 첨가군에서 높게 나타났으며(p<0.05), 건조 중량은 cellulose군에서 가장 높았다. 분변으로 배설된 단백질 및 직질의 함량은 무섬유식이군에 비해 식이섬유 첨가군에서 유의적으로 높았으며 (p<0.05), 따라서 단백질과 지질의 소화율은 무섬유식이군에 비해 cellulose군과 sodium alginate군에서 유의적으로 낮았다(p<0.05). 췌장의 amylase와 lipase 활성은 세군간에 유의적인 차이가 없었으나 무섬유식이군에 비해 식이섬유군에서 다소 낮은 경향을 보였으며, 췌장의 Prntease 활성은 무섬유식이군과 cellulose군에 비해 sodium alginate군에서 유의적으로 낮았다(p<0.05). 췌장의 DNA 및 RNA 함량은 식이군간에 유의적인 차이가 없었으나 췌장 단백질 함량은 무섬유식이군에 비해 식이섬유군에서 높게 나타났다(p<0.05). SEM과 LM을 이용한 연구에서 식이섬유의 섭취는 주름을 가진 넓은 잎사귀모양의 융모세포와 goblet cell의 증식을 유도하는 것을 확인하였다. 이상의 결과를 종합해 볼 때, 식이섬유의 섭취는 지방과 단백질의 흡수를 억제하여 영양소의 소화율을 떨어뜨리며 소화기관의 형태적.생화학적 변화를 유도함을 알 수 있었다.

• 한국식품영양학회지
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• 제15권2호
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• pp.112-118
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• 2002

분열효모 S. pombe의 포자형성은 배지상의 질소원 고갈에 의해 유도되어지며 감수분열로부터 포자형성에 도달하는 과정에는 다수의 특이적인 유전자들이 관여하고 있다. 본 실험에서는 S. pombe genomic library 형질 전환법으로 spo5 유전자를 상보하는 clone을 screening한 후, sport 유전자를 단리하였다$^{8)}$ . 전포자막 구축에 필수적인 sport 유전자를 보유하는 약 5kb의 DNA 단편을 대장균, 효모 shuttle vector pTB248'의 Hind III 부위에 subclonning하였다. 그리고 이 DNA단편으로부터 제한 효소 지도를 작성하여(Fig. 2), spo5 변이체의 상보 능력을 조사하였다 (Fig. 3). 결과에서 서술한 바와 같이 상보능력은 동일하였으며, 이러한 상보성 실험 결과로부터 삽입된 단편상의 유전자 발현은 벡터의 promoter로부터 전사가 일어나는 것이 아니라, 삽입 단편상의 효모 고유의 promoter 에 의해서 전사가 일어나는 것으로 확인되었다. 따라서 clone화 한 DNA 단편 배열상에는 변역영역뿐만 아니라 promoter 영역이 포함된 것으로 판단되었다. 결실변이 도입 해석으로부터, spo5 유전자는 Sma I 부터 Hind m의 3kb 영역에 존재하였고 (Fig. 3), Nor-thern분석에 의해서 spo5 유전자의 전사를 조사한 결과, spo5 -mRNA는 Sma I 부터 Hind III 의 3kb 영 역에서 약2.5kb 크기로 검출되었다. 이 단편의 유전해석으로 부터 약 2.5kb의 전사산물은 최대 800개의 아미노산 잔기를 code하는 단백질로 판단되었다(Fig. 4). 그리고, Northern 분석법에 의해서 spo5 유전자의 전사를 조사한 결과, 서술한 바와 같이, 이 유전자는 질소기아 조건하에서만 유전자가 발현되는 것을 확인하였다(Fig. 4-2.5kb 단편).었다. 그리고 Edman법으로 결정한 PPIase의 39아미노산 잔기가 이 배열내에 완전히 보존되어 있었다. 이 결과로부터 이 ORF는PPIase구조 유전자의 1/3에 해당하는 단편임을 확인하였다. training system to a dangerous work like as "Interruption-free live-line work exchanging COS(Cut-Out-Switch)". In this program, the user works with a instruction on the window and speaker and can't work other tasks until each part of the task completed. The workers using this system can use their hands and viewpoint movement as he is in a real environment but the trainee can't use all parts and senses of a real body with the current VR technology. Despite of this weak point, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has a high potentiality.) 야생화 초지(NWP, IWP)는 관행 혼파초지나 하번초 혼파초지에 비하여 동물상이 다양하고 많게 분포되었으며 그중 외국산 야생화초지의 동물 개체수가 가장 많게 나타났다. 이상의 결과를 종합할 때, 야생화 초지는 봄부터 가을까지 야생화가 지속되었고, 양서류 및 곤충의 개체 수가 증가되었던 것으로 보아 야생화 초지의 공익적인 측면에서의 활용 가능성도 클 것으로 기대된다

• IMMUNE NETWORK
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• 제1권1호
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• pp.77-86
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• 2001

Background: Hepatitis C virus(HCV), a family of Flaviviridae, has a host cell-derived envelope containing a positive-stranded RNA genome, and has been known as the maj or etiological agent for chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. There remains a need to dissect a molecular mechanism of pathogenesis for the development of therapeutic and effective preventive measure for HCV. Identification of cellular receptor is of central importance not only to understand the viral pathogenesis, but also to exploit strategies for prevention of HCV. This study was aimed at identifying peptide mimotopes inhibiting the binding of E2 protein of HCV to MOLT-4 cell. Methods: In this study, phage peptide library displaying a random peptides consisting of 7 or 12 random peptides was employed in order to pan against E2 protein. Free HCV particles were separated from the immune complex forms by immunoprecipitation using anti-human IgG antibody, and used for HCV-capture ELISA. To identify the peptides inhibiting E2-binding to MOLT-4 cells, E2 protein was subj ect to bind to MOLT-4 cells under the competition with phage peptides. Results: Several phage peptides were selected for their specific binding to E2 protein, which showed the conserved sequence of SHFWRAP from 3 different peptide sequences. They were also able to recognize the HCV particles in the sera of HCV patients captured by monoclonal antibody against E2 protein. Two of them, showing peptide sequence of HLGPWMSHWFQR and WAPPLERSSLFY respectively, were revealed to inhibit the binding of E2 protein to MOLT-4 cell efficiently in dose dependent mode. However, few membrane-associated receptor candidates were seen using Fasta3 programe for homology search with these peptides. Conclusion: Phage peptides containing HLGPWMSHWFQR and WAPPLERSSLFY respectively, showed the inhibition of E2-binding to MOLT-4 cells. However, they did not reveal any homologues to cellular receptors from GenBank database. In further study, cellular receptor could be identified through the screening of cDNA library from MOLT-4 or hepatocytes using antibodies against these peptide mimotopes.