• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.588-591
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• 2000

Sphingoliped 대사의 율속효소인 serine palmitoyl transferase(SPT)와 acid ceramidase의 연구를 위하여 인간의 SPTII 유전자와 acid ceramidase 유전자의 5‘-upstream region을 얻었다. 사람의 대장암세포인 HT29 cell로부터 genomic DNA를 얻고 GenomeWalker kit를 이용하였으며 2690bp의 SPTII promoter와 2028bp 및 1034bp의 acid ceramidase promoter의 fragment들을 얻을 수 있었다. 이들 DNA 조각들을 T7Blue vector에 subcloning하여 sequencing하였으며 이들이 사람의 SPTII 및 acid ceramidase gene의 5’-upstream region임을 확인하였다. 동물세포에서의 promoter activity를 측정하기위하여 firefly luciferase를 reporter gene으로 하는 pGL2-enhancer vector와 pGL2-basic vector에 subcloning하였으며 pRL-TK vctor와 함께 HT29 cell 및 HepG2 cell에 cotransfection 시킨 후 luciferaseg활성을 측정한 결과 같은 양의 DNA로는 사람의 SPTII promoter와 acid ceramidase promoter는 pRL-TK에 비하여 transfection efficiency가 아주 낮았으며 promoter 연구를 위하여는 pRL-TK vector의 양을 1/100으로 줄이는 것이 적당하였으며 HT29 cell보다는 HepG2 cell에 더 높은 발현율을 보였다.

• BMB Reports
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• 제44권5호
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• pp.298-305
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• 2011

Most intracellular reactive oxygen species (ROS), especially superoxide anion ($O_2^{{\bullet}_-}$) that is converted from oxygen, are overproduced by excessive electron leakage from the mitochondrial respiratory chain. Intracellular oxidative stress that damages cellular components can contribute to lifestyle-related diseases such as diabetes and arteriosclerosis, and age-related diseases such as cancer and neuronal degenerative diseases. We have previously demonstrated that the excessive mitochondrial $O_2^{{\bullet}_-}$ production caused by SDHC mutations (G71E in C. elegans, I71E in Drosophila and V69E in mouse) results in premature death in C. elegans and Drosophila, cancer in mouse embryonic fibroblast cells and infertility in transgenic mice. SDHC is a subunit of mitochondrial complex II. In humans, it has been reported that mutations in SDHB, SDHC or SDHD often result in inherited head and neck paragangliomas (PGLs). Recently, we established Tet-mev-1 conditional transgenic mice using our uniquely developed Tet-On/Off system, which equilibrates transgene expression to endogenous levels. These mice experienced mitochondrial respiratory chain dysfunction that resulted in $O_2^{{\bullet}_-}$ overproduction. The mitochondrial oxidative stress caused excessive apoptosis leading to low birth weight and growth retardation in the neonatal developmental phase in Tet-mev-1 mice. Here, we briefly describe the relationships between mitochondrial $O_2^{{\bullet}_-}$ and aging phenomena in mev-1 animal models

• BMB Reports
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• 제31권6호
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• pp.595-599
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• 1998

To investigate conformational information of a low oxygen affinity recombinant hemoglobin (rHb) containing $96Val{\rightarrow}Trp$ mutation at the ${\alpha}96$ position, we ave produced rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr$), using the Escherichia coli expression system and site-directed mutagenesis. The oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Phe$) is similar to that of human normal adult hemoglobin (Hb A). However, the oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Tyr$) showed much lower oxygen affinity than Hb A which is similar to that of rHb (${\alpha}96Val{\rightarrow}Tyr$), providing an opportunity as a potential candidate for a hemoglobin-based blood substitute. Both rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr)$ showed high cooperativity in oxygen binding. IH-NMR spectroscopy shows that both rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr$) have very similar tertiary structure around the heme pockets and uaternary structure in the ${\alpha}_1/{\beta}_2$ subunit interface ompared to Hb A. The low oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Tyr$) has been suggested to be due to a hydrogen bond caused by an extra hydroxyl group not present in rHb (${\alpha}96Val{\rightarrow}Phe$). However, investigation of the carbonmonoxy form of rHb (${\alpha}96Val{\rightarrow}Phe$) and (${\alpha}96Val{\rightarrow}Try$) in the presence of inositol hexaphosphate at low temperature suggests that low oxygen affinity of (${\alpha}96Val{\rightarrow}Try$) may arise from a mechanism different to that of rHb (${\alpha}96Val{\rightarrow}Trp$).

• Parasites, Hosts and Diseases
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• 제54권1호
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• pp.67-70
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• 2016

We report here a human case of Taenia asiatica infection which was confirmed by genetic analyses in Dali, China. A patient was found to have symptoms of taeniasis with discharge of tapeworm proglottids. By sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, we observed nucleotide sequence identity of 99% with T. asiatica and 96% with T. saginata. Using the cytochrome b (cytb) gene, 99% identity with T. asiatica and 96% identity with T. saginata were found. Our findings suggest that taeniasis of people in Dali, China may be mainly caused by T. asiatica.

• Animal cells and systems
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• 제13권3호
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• pp.351-356
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• 2009

Ciliates are undoubtedly one of the most diverse protozoans that play a significant role in ecology. However, molecular examination, based on comparing the DNA sequences, has been done on a limited number of the species. Because most ciliates are uncultivable and their population sizes are often too small, it is usually difficult to obtain sufficient genomic DNA required for PCR based experiments. In the present study, we evaluated the effectiveness of four commercial DNA extraction procedures that extract high quality genomic DNA from a single ciliate cell. It was discovered that RED Extract-N-$Amp^{TM}$ PCR kit is the best method for removing PCR-inhibiting substances and minimizing DNA loss during purification. This method can also amplify more than 25 reactions of PCR. In addition, this technique was applied to single cells of 19 species belonged to 7 orders under 5 classes that isolated from mixed natural populations. Their small subunit ribosomal DNA (SSU rDNA) was successfully amplified. In summary, we developed a simple technique for the high-yield extraction of purified DNA from a single ciliate cell that may be more useful for rare ciliates, such as tiny and uncultivable marine microbes.

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.287-291
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• 2009

The ${\alpha}/{\beta}$-tubulin heterodimer is the basic subunit of microtubules in eukaryotes. Polyclonal antibodies specific to recombinant ${\alpha}$-tubulin of Giardia lamblia were made, and found effective as a probe to specifically detect G. lamblia by immunofluorescence assays. Nucleotide sequences of ${\alpha}$-tubulin genes were compared between G. lamblia WB and GS strains, prototypes of assemblage A and assemblage B, respectively. A set of primers was designed and used to amplify a portion of the ${\alpha}$-tubulin gene from G. lamblia. PCR-RFLP analysis of this ${\alpha}$-tubulin PCR product successfully differentiated G. lamblia into 2 distinct groups, assemblages A and B.Theresults indicate that ${\alpha}$-tubulin can be used as a molecular probe to detect G.lamblia.

• Carbon letters
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• 제15권2호
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• pp.105-112
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• 2014

Wastewater from textile industries is a major cause of water pollution in most developing countries. In order to address the issues of water pollution and high cost for treatment processes, the use of an inexpensive and environmentally benign adsorbents has been studied. The objective was to find a better alternative to the conventional methods. Lemon grass waste (ash) collected from a lemon grass stream distillation subunit in Bhutan was tested for dye removal from aqueous solutions. The study investigated the removal of methylene blue using the following operational parameters: initial concentration (100-600 mg/L), contact time, adsorbent dose (0.1-0.55 gm/100 mL), and pH (3-10). It was found that the percentage removal of dye increased with a decrease of the initial concentration and increased contact time and dose of adsorbent. The basic pH solution of dye showed better adsorption capacity as compared to the acidic dye solution. Langmuir and Freundlich adsorption isotherms were fitted to the data well. Data fitted better to Lagergren pseudo 2nd order kinetics than a 1st order kinetic model. Surface morphology was also examined via scanning electron microscopy. An elemental analysis was also carried out and the chemical composition and functional groups were analyzed using energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy techniques, respectively. The obtained results indicate that lemon grass ash could be employed as a low cost alternative to commercial activated carbon in wastewater treatment for the removal of dyes.

• BMB Reports
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• 제46권12호
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• pp.567-574
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• 2013

Liver plays a major role in maintaining glucose homeostasis in mammals. Under fasting conditions, hepatic glucose production is critical as a source of fuel to maintain the basic functions in other tissues, including skeletal muscle, red blood cells, and the brain. Fasting hormones glucagon and cortisol play major roles during the process, in part by activating the transcription of key enzyme genes in the gluconeogenesis such as phosphoenol pyruvate carboxykinase (PEPCK) and glucose 6 phosphatase catalytic subunit (G6Pase). Conversely, gluconeogenic transcription is repressed by pancreatic insulin under feeding conditions, which effectively inhibits transcriptional activator complexes by either promoting post-translational modifications or activating transcriptional inhibitors in the liver, resulting in the reduction of hepatic glucose output. The transcriptional regulatory machineries have been highlighted as targets for type 2 diabetes drugs to control glycemia, so understanding of the complex regulatory mechanisms for transcription circuits for hepatic gluconeogenesis is critical in the potential development of therapeutic tools for the treatment of this disease. In this review, the current understanding regarding the roles of two key transcriptional activators, CREB and FoxO1, in the regulation of hepatic gluconeogenic program is discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.253-262
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• 2000

Aspergillus is considered to be an attractive host for heterologous protein production because of its safety and ability to secrete large amounts of proteins. In order to obtain high productivity, thus far promoters of amylases have been most widely used in A. oryzae. Recent progress in cloning and expression analysis, including EST sequencing, revealed that glycolytic genes represent some of those most strongly expressed in A. oryzae. Therefore, promoters of glycolytic genes could be important alternatives to promoters of amylases because lower amounts of proteases are produced in the presence of glucose. Several A. oryzae transcription factors responsible for the induction and/or maximum expression of many industrially important genes encoding amylases and proteases have been cloned and characterized. In addition to the transcriptional regulatory factors, the gene encoding the largest subunit of RNa polymerase II, constituting the basic transcription machinery, has also been cloned from A. oryzae. This recently acquired understanding of the details of transcriptional regulatory mechanisms and factors will facilitate engineering flexible controls for the expression of proteins important for the fermentation industries.

• Animal Systematics, Evolution and Diversity
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• 제25권2호
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• pp.167-178
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• 2009

Two poorly known and often confused pleurostomatid ciliates, Litonotus paracygnus Song, 1994 and L. pictus Gruber, 1884, were collected from the coastal waters of Yeonggeumjeong and Bongpo-port, Gangwondo in the East Sea and from the Iwon tide embankment near Ganwol-do, Chungcheongnam-do in the Yellow Sea, Korea. These species were described based on live observations, the protargol-impregnation and morphometrics of the species. Also provided are their diagnoses. The small subunit ribosomal DNA (SSU rDNA) sequences of these species were compared with previously known sequences of related species. The diagnostics of the two Litonotus species are as follows. L. paracygnus: 150-300 $\mu$m long in vivo, strongly contractile neck region, two ellipsoid macronuclei (Ma) and one micronucleus (Mi), 7 left (LSK) and 11-14 right somatic kineties (RSK), 2-4 contractile vacuoles (CV) located on the posterior end, extrusemes (Ex) distributed on the anterior region of the ventral margin only. L. pictus: about 200-600 $\mu$m long in vivo, extremely contractile, beautiful body color with rows of yellow to yellow-brownish cortical pigment granules, 12-21 Ma arranged in moniliform pattern, infrequently vermiform, 7-11 LSK and 18-26 RSK, several CV located on both margins, Ex distributed on the anterior region of the ventral margin only. In this study, this genus was firstly recorded in Korea.