• 제목/요약/키워드: Internal cleavage

검색결과 86건 처리시간 0.023초

Isolation and Characterization of Bacillus sp. KD1014 Producing Carboxymethyl-Cellulase (Isolation and characterization of Bacillus sp. KD1014 producing carboxymethyl-cellulase)

  • Lee, Kyung Dong;Kim, Jong Ho;Kim Hoon
    • Journal of Microbiology
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    • 제34권4호
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    • pp.305-310
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    • 1996
  • A microorganism producing carboxymethyl-cellulase (CMCase) was isolated from 300 soil and compost samples. The isolate was identified as Bacillus sp. by $Biolog^{TM}$ test and fatty acid analysis, and named as Bacillus sp. KD1014. The isolate could degrade, in addition to CMC, various kinds of polysaccharides such as levan, xylan, starch, and filter paper but hardly degrade microcrystalline Avicel. The optimum growth and CMCase production of the isolate was observed between 16-and 25 hr-culture at 45$^{\circ}C$ and pH 5.0. The maximum CMCase activity was observed at pH 4.5 and 6$0^{\circ}C$. The CMCase was found to bind to Avicel. The CMCase was internally cleaved as growth continued. When crude supernatant was used for activity staining, three major bands were detected on a native gel, however, only one major band was detected on a denaturating gel after removal of the detergent.

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기체크로마토그래피법에 의한 티아민 분석 (Determination of Thiamin by Gas-chromatography)

  • 유지상;문동철;홍성화;한건;김박광
    • 약학회지
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    • 제33권3호
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    • pp.156-160
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    • 1989
  • A gas-chromatographic determination method of thiamin which use a quantitative cleavage of thiamin to 4-methyl-5-(2-hydroxyethyl)thiazol [I] and solvent extraction of the analyte prior to GC injection was modified. A column chromatographic procedure using a reversed phase, high capacity solid phase cartridge was applied to the clean-up of the analyte. Thiazol derivative[I] was quantitatively recovered upon the column method. Acetanilide, an internal standard, has a good recovery through the analytical procedure. The method has analytical precision of 2% or less in the coefficient of variation.

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포천 화강암의 결 이방성이 수압파쇄거동에 미치는 영향 (Influence of the Cleavage Anisotropy of Pocheon Granite on Hydraulic Fracturing Behaviour)

  • 정성규;장리;염선;김광염;민기복
    • 터널과지하공간
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    • 제26권4호
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    • pp.327-337
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    • 2016
  • 본 연구에서는 화강암 내부의 미세균열 분포에 따른 이방성이 수압파쇄실험 결과에 미치는 영향을 평가하였다. 압력증가율을 일정하게 설정하여 수압파쇄실험을 수행한 결과, 원주방향(주입정 방향과 직교)으로 리프트면이 분포한 시료의 파쇄압력이 가장 낮게 측정되었고, 이는 미세균열의 밀도가 높기 때문이다. 수압파쇄실험과정에서 시료 내부의 변화가 발생하는 주입압력의 크기와 유체 주입속도의 변화 또한 결방향에 따라 분포한 미세균열의 밀도와 관계가 있는 것으로 판단된다. 유체주입속도를 일정하게 설정하여 수압파쇄실험을 수행하였을 경우, 상대적으로 미세균열의 밀도가 높은 리프트면이 원주방향으로 분포된 시료에서 주입압력증가율이 낮게 나타났고, 유체가 침투될 수 있는 균열망이 상대적으로 적게 형성된 그레인면 및 하드웨이면이 원주방향으로 분포된 시료에서는 압력증가율이 높게 나타났다. X-ray CT 촬영을 통해 시료 내부에 생성된 균열의 방향을 확인한 결과, 대부분의 시료에서 리프트면 혹은 그레인면과 평행한 방향으로 균열이 생성된 것을 확인하였고, 이는 암석 내에 상대적으로 미세균열의 밀도가 높아서 분리성이 크기 때문이다.

전자회절도형을 이용한 장석의 구조 분석에 대한 고찰 (An Investigation on Structural Analysis of Feldspars by Electron Diffraction Patterns)

  • 김윤중;이영부;박병규;이정후
    • 한국광물학회지
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    • 제17권2호
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    • pp.177-187
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    • 2004
  • Au 내부 표준시편을 이용하여 일반 전자회절도형에서도 알바이트와 올리고클레이스의 격자 상수 값을 1% 이내의 오차범위로 얻었다. 자연산 올리고클레이스 시료의 전자회절도형 지도를 작성하였고, 11개 지점의 정대축 전자회절도형을 얻었다 이러한 작업은 삼사정계민 장석으로부터 신뢰성 있는 전자현미경 연구 결과를 얻기 위해서는 필수적인 과정이다. 장식의 {001} 벽개면과 TEM의 양측경사 시료지지대를 이용하면 장석의 구조/화학 분석에 필요한 다음과 같은 정보를 획득할 수 있다: 알칼리 장석은 [001] 방향에서 * 값을, [100] 방향에서 $\alpha$* 값을 측정하여 $\alpha$* - * plot을 함으로써 미세 영역에서 Si-Al ordering 상태 및 화학 조성을 예측할 수 있다. Na-rich한 사장석은 [001] 방향에서 * 값을 측정하여 Si-Al ordering 상태를 예측할 수 있다. Na-poor한 사장석은 [100] 방향에서 e-reflection의 유무, 회절강도 및 위치 변화를 측정하여 구조 및 화학을 예측할 수 있다.

계혈등 물추출물의 항산화 및 간보호효과 (Antioxidant Effect and Liver Protection Effect of Spatholobi Caulis Water Extract)

  • 이재준;최홍식;김승모
    • 대한본초학회지
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    • 제26권3호
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    • pp.47-56
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    • 2011
  • Objectives : This study investigated whether the water extract of Spatholobi Caulis (SCE) has the ability to protect hepatocyte against oxidative stress induced by tert-butylhydroperoxide (tBHP) in vitro and $CCl_4$ in vivo. Methods : In vitro, HepG2 cells pre-treated with Spatholobi Caulis water extract (1, 3, 10, $30{\mu}g$/ml) for 12h and further incubated with tBHP ($100{\mu}M$) for the next 12h. Cell viability was assessed by MTT assay. In vivo, rats were orally administrated with the aqueous extract of Spatholobi Caulis (SCE; 50, 100 mg/kg) for 4 days and then, injected with $CCl_4$ 1 mg/kg body weight to induce acute liver damage. Results : Treatment with SCE inhibited cell death induced by tBHP, as evidenced by alterations in the levels of the proteins associated with apoptosis:SCE prevented a decrease in $Bcl_2$, and cleavage of poly(ADP-ribose)polymerase and pro-caspase-3. Moreover, SCE inhibited the ability of tBHP to generate $H_2O_2$ production, thereby restoring GSH content. Moreover, SCE treatments in rats effectively decreased liver injuries induced by a single dose of $CCl_4$, as evidenced by decreases in hepatic degeneration and inflammation as well as plasma alanine aminotransferase and lactate dehydrogenase activities. Consistently, treatments of SCE also protected liver in rats stimulated by $CCl_4$, as indicated by restoration GSH and prevention of MDA in the liver. Conclusions : SCE has the ability 1) to protect hepatocyte against oxidative stress induced by tBHP and 2) to prevent $CCl_4$-inducible acute liver toxicity. Present findings may be informative not only in elucidating the pharmacological mechanism of Spatholobi Caulis, but in determining its potential application for oxidative cellular damage in the liver.

길경이 인체 폐암세포에 미치는 영향에 대한 실험적 연구 (Apoptotic Cell Death of Human Lung Carcinoma A549 Cells by an Aqueous Extract from the Roots of Platycodon grandiflorum)

  • 이성열;김원일;박동일
    • 동의생리병리학회지
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    • 제17권4호
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    • pp.1019-1030
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    • 2003
  • Platycodi Radix, the root of Platycodon grandiflorum, commonly known as Doraji, is used as a traditional oriental medicine. Extracts from the roots of P. grandiflorum have been reported to have wide ranging health benefits. In the present study, we investigated the effects of an aqueous extract from the roots of P. grandiflorum (AEPG) on the growth of human lung carcinoma A549 cells. Results obtained are as fellow; AEPG treatment resulted in the inhibition of the cell viability of A549 cells in a concentration-dependent manner. Upon treatment with AEPG, A549 cells developed many of the hallmark features of apoptosis, including condensation of chromatin. Flow cytometry analysis confirmed that AEPG increased populations of apoptotic-sub G1 phase. Western blot and RT-PCR analyses indicated that the expressions of Bcl-2 was down-regulated but Bax was up-regulated in AEPG-treated A549 cells. AEPG-induced apoptotis of A549 cells was associated with rroteolytic cleavage and activation of caspase-3, release of cytochrome c from mitochondria into cytosol and down-regulation of Akt and phospho-Akt proteins in a dose-dependent manner. Induction of apoptosis by AEPG treatment was associated with inhibition and/or degradation of apoptotic target proteins such as poly(ADP-ribose) polymerase, β-catenin and phospholipase C-γ 1. AEPG treatment inhibited the levels of cyclooxygenases protein of A549 cells, which was associated with the inhibition of prostaglandin E2 accumulation in a concentration-dependent fashion. Taken together, these findings suggest that P. grandiflorum has strong potential for development as an agent for prevention against human lung cancer.

Induction of Forkhead Class box O3a and apoptosis by a standardized ginsenoside formulation, KG-135, is potentiated by autophagy blockade in A549 human lung cancer cells

  • Yao, Chih-Jung;Chow, Jyh-Ming;Chuang, Shuang-En;Chang, Chia-Lun;Yan, Ming-De;Lee, Hsin-Lun;Lai, I-Chun;Lin, Pei-Chun;Lai, Gi-Ming
    • Journal of Ginseng Research
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    • 제41권3호
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    • pp.247-256
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    • 2017
  • Background: KG-135, a standardized formulation enriched with Rk1, Rg3, and Rg5 ginsenosides, has been shown to inhibit various types of cancer cells; however, the underlying mechanisms are not fully understood. In this study, we explored its effects in A549 human lung cancer cells to investigate the induction of Forkhead Class box O3a (FOXO3a) and autophagy. Methods: Cell viability was determined by sulforhodamine B staining. Apoptosis and cell cycle distribution were analyzed using flow cytometry. The changes of protein levels were determined using Western blot analysis. Autophagy induction was monitored by the formation of acidic vesicular organelles stained with acridine orange. Results: KG-135 effectively arrested the cells in G1 phase with limited apoptosis. Accordingly, a decrease of cyclin-dependent kinase-4, cyclin-dependent kinase-6, cyclin D1, and phospho-retinoblastoma protein, and an increase of p27 and p18 proteins were observed. Intriguingly, KG-135 increased the tumor suppressor FOXO3a and induced the accumulation of autophagy hallmark LC3-II and acidic vesicular organelles without an increase of the upstream marker Beclin-1. Unconventionally, the autophagy adaptor protein p62 (sequestosome 1) was increased rather than decreased. Blockade of autophagy by hydroxychloroquine dramatically potentiated KG-135-induced FOXO3a and its downstream (FasL) ligand accompanied by the cleavage of caspase-8. Meanwhile, the decrease of Bcl-2 and survivin, as well as the cleavage of caspase-9, were also drastically enhanced, resulting in massive apoptosis. Conclusion: Besides arresting the cells in G1 phase, KG-135 increased FOXO3a and induced an unconventional autophagy in A549 cells. Both the KG-135-activated extrinsic FOXO3a/FasL/caspase-8 and intrinsic caspase-9 apoptotic pathways were potentiated by blockade of autophagy. Combination of KG-135 and autophagy inhibitor may be a novel strategy as an integrative treatment for cancers.

백혈병 세포주 Jurkat의 세포고사 유도 및 세포주기 억제에 미치는 합산피 추출물의 효과 (Effects of the Water Extract from Albizzia julibrissin on Apoptosis and Cell Cycle Progression in the Human Leukemic Jurkat Cells)

  • 박영준;정우철;정대영;이용운;이인;이기상;전병훈;성강경;문병순
    • 동의생리병리학회지
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    • 제17권6호
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    • pp.1383-1392
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    • 2003
  • Apoptosis is a morphologically and biochemically district form of cell death that occurs in many different cell types in a wide variety of organisms. Albizzia julibrissin belonging the family Leguminosae has been used for the treatment of contusion, sore throat, amnesia, and insomnia in oriental traditional medicine. This study investigates whether the water extract of A. julibrissin induce apoptotic cell death in Jurkat T-acute lymphoblastic leukemia (ALL) cells. Jurkat cells were increased inhibitions of cell viability in a concentration-dependent manner by A. julibrissin. This herbal medicine also caused apoptosis as measured by cell morphology and DNA fragmentation. The capability of A. julibrissin to induce apoptosis was associated with proteolytic cleavage of specific target proteins such as poly (ADP-ribose)polymerase (PARP) and beta-catenin proteins suggesting the possible involvement of caspases. Our result showed that Bcl-2 and Bax protein levels were not changed in all A. julibrissin-treated groups compared to control group. These results suggest that A. julibrissin-mediated apoptosis is independent with Bcl-2 related signaling pathway in this cells. The purpose of the present study is also to investigate the Effect of A. julibrissin on cell cycle progression. Our results showed that G1 checkpoint related gene products (cyclin D1, cyclin dependent kinase 4, retinoblastoma, E2F1) were decreased in their protein levels in a dose-dependent manners after treatment of the extract. These results indicate that the increase of apoptotic cell death by A. julibrissin may be due to the inhibition of cell cycle progression in wild type p53-lacking Jurkat cells.

Schedule-Dependent Effect of Epigallocatechin-3-Gallate (EGCG) with Paclitaxel on H460 Cells

  • Park, Sunghoon;Kim, Joo-Hee;Hwang, Yong Il;Jung, Ki-Suck;Jang, Young Sook;Jang, Seung Hun
    • Tuberculosis and Respiratory Diseases
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    • 제76권3호
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    • pp.114-119
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    • 2014
  • Background: Epigallocatechin-3-gallate (EGCG), a major biologically active component of green tea, has anti-cancer activity in human and animal models. We investigated the schedule-dependent effect of EGCG and paclitaxel on growth of NCI-H460 non-small cell lung cancer cells. Methods: To investigate the combined effect of EGCG (E) and paclitaxel (P), combination indices (CIs) were calculated, and cell cycle analysis was performed. For the effect on cell apoptosis, western blot analysis was also performed. Results: CI analysis demonstrated that both concurrent and sequential E ${\rightarrow}$ P treatments had antagonistic effects (CIs >1.0), but sequential P ${\rightarrow}$ E had synergistic effects (CIs <1.0), on the growth inhibition of NCI-H460 cells. In the cell cycle analysis, although paclitaxel induced $G_2/M$ cell cycle arrest and increased the sub-G1 fraction, concurrent EGCG and paclitaxel treatments did not have any additive or synergistic effects compared with the paclitaxel treatment alone. However, western blot analysis demonstrated that sequential P ${\rightarrow}$ E treatment decreased the expression of Bcl-2 and procaspase-3 and increased poly(ADP-ribose) polymerase (PARP) cleavage; while minimal effects were seen with concurrent or sequential E ${\rightarrow}$ P treatments. Conclusion: Concurrent or sequential E ${\rightarrow}$ P treatment had opposite effects to P ${\rightarrow}$ E treatment, where P ${\rightarrow}$ E treatment showed a synergistic effect on growth inhibition of NCI-H460 cells by inducing apoptosis. Thus, the efficacy of EGCG and paclitaxel combination treatment seems to be schedule-dependent.

Soluble Expression of Recombinant Olive Flounder Hepcidin I Using a Novel Secretion Enhancer

  • Lee, Sang Jun;Park, In Suk;Han, Yun Hee;Kim, Young Ok;Reeves, Peter R.
    • Molecules and Cells
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    • 제26권2호
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    • pp.140-145
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    • 2008
  • Expression of olive flounder hepcidin I (HepI) fused with truncated OmpA signal peptides ($OmpASP_{tr}$) as directional signals does not produce soluble fusion proteins. However, by inserting amino acid segments (xxx) varying in pI and hydrophobicity/hydrophilicity into a leader sequence containing a truncated OmpASP ($OmpASP_{tr}$) and a factor Xa cleavage site (Xa) [$OmpASP_{tr}{\mid}(xxx){\mid}Xa$], we were able in some cases to express soluble recombinant HepI. Soluble expression of the recombinant protein strongly correlated with (xxx) insertions of high pI and hydrophilicity. Therefore, we modified the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ sequence by inserting Arg and Lys into (xxx) to increase the hydrophilicity of the signal peptide region. These modifications enhanced the expression of soluble recombinant HepI. Hydropathic profile analysis of the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ HepI fusion proteins revealed that the transmembrane-like domains derived from the $OmpASP_{tr}{\mid}(xxx){\mid}Xa$ sequence were larger than the internal positively charged domain native to HepI. It should therefore be possible to overcome the obstacle of internal positively charged domains to obtain soluble expression of recombinant proteins by monitoring the hydrophilicity and hydropathic profile of the signal peptide region using a computer program.