• 제목/요약/키워드: Internal cleavage

검색결과 86건 처리시간 0.031초

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

  • Yoo, Ji-Sang;Moon, Dong-Cheul;Hong, Sung-Hwa;Han, Kun;Kim, Bak-Kwang
    • YAKHAK HOEJI
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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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Influence of the Cleavage Anisotropy of Pocheon Granite on Hydraulic Fracturing Behaviour (포천 화강암의 결 이방성이 수압파쇄거동에 미치는 영향)

  • Jung, Sung-Gyu;Zhuang, Li;Yeom, Sun;Kim, Kwang-Yeom;Min, Ki-Bok
    • Tunnel and Underground Space
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    • 제26권4호
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    • pp.327-337
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    • 2016
  • In this study, laboratory hydraulic fracturing tests are carried out to evaluate the effects of the cleavage anisotropy of Pocheon granite. Breakdown pressure is smaller when cracks are generated to the direction of rift plane in constant pressurization rate condition because of higher microcracks density. Besides not only injection rate changes but also the amount of injection pressure for fracture initiation and crack expansion is detected while testing due to internal deformation. Pressurization rate is higher while hydraulic fracture testing with constant injection rate condition in case of the specimen which has rift plane perpendicular to borehole because there are much flow paths to penetrate compared to the specimen which has hardway plane perpendicular to borehole. Observation by X-ray CT scanning shows that almost all of cracks due to hydraulic fracturing are generated to the direction of plane which has higher microcrack density that is rift plane or grain plane.

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

  • 김윤중;이영부;박병규;이정후
    • Journal of the Mineralogical Society of Korea
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    • 제17권2호
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    • pp.177-187
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    • 2004
  • Measurements of the lattice parameters of albite and oligoclase from electron diffraction patterns with the Au internal standard resulted in errors of less than 1 %. An electron diffraction map for natural oligoclase samples was constructed and 11 stations of zone-axes diffraction patterns were obtained. This process is indispensible for reliable TEM studies of triclinic feldspars. Utilizing the [001] cleavage plane of feldspar and the double-tilting TEM holder the following information is obtainable: Si-Al ordering and chemistry of alkali feldspars could be estimated from the $\alpha$* - * plot, where * is measured from the [001] orientation, while $\alpha$* is measured from the [100] orientation. Si-Al ordering of Na-rich plagioclase could be estimated from * [001] patterns. Structure and chemistry or Na-poor plagioclase could be estimated from existence of e-reflections, their intensity variations as well as their positional changes.

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

  • Lee, Jae-Jun;Choi, Hong-Sik;Kim, Seung-Mo
    • The Korea Journal of Herbology
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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.

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

  • Lee Sung Yeoul;Kim Won Ill;Park Dong Il
    • Journal of Physiology & Pathology in Korean Medicine
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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.

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

  • Park Young Jun;Jung Woo Cheal;Jeong Dae Young;Lee Yong Un;Lee In;Lee Key Sang;Jeon Byung Hun;Sung Kang Keyng;Moon Byung Soon
    • Journal of Physiology & Pathology in Korean Medicine
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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.