• 생명과학회지
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• 제29권10호
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• pp.1159-1163
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• 2019

남성호르몬 감소와 관련된 남성갱년기에 대한 관심이 고조되고 있지만, 남성호르몬의 정량을 위해 항체를 이용하는 고가의 kit가 이용되고 있다. 본 연구에서는 in vitro 전사 활성 시험법을 이용하여 남성 스테로이드호르몬의 활성 혹은 농도를 검증하는 시스템을 구축하였다. 테스토스테론-AR (androgen receptor) 복합체와 반응하는 ARE-AdE1bTATA 염기서열이 삽입되고 리포터로 luciferase를 발현하는 테스토스테론 유사활성 검증 리포터 플라스미드인 pGL2-Neo-ARE-AdE1BTATA를 제조하고, 인체 전립선암 세포인 LNcap-LN3 세포에 stable transfection을 실시하였다. 구축된 LNcap-LN3/pGL2-Neo-ARE-AdE1BTATA TCD (testosterone compound detection) 시스템은 표준물질인 테스토스테론의 $10^{-13}{\sim}10^{-8}M$ 범위에서 농도 증가에 비례하는 정량성을 보였다. 이 연구에서 확립된 in vitro TCD 시스템을 이용하면 천연물 유래 테스토스테론 유사물질 및 테스토스테론 저하물질의 대량 탐색 등이 가능할 것이므로, 건강기능성 식품이나 의약품 신소재의 개발에 기여할 것이다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.534-537
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• 2002

본 연구에서는 기능성 식품 첨가물 소재 또는 의약품으로 사용 가능한 한천올리고당의 대량생산을 위하여 agarase 생산균주인 Bacillus cereus ASK202에 대해 유전자 cloning 방법을 이용하여 한천분해효소 고생산성 균주로의 개발을 시도하였다. 원균주의 chromosomal DNA를 무작위적으로 절단하여 agarase를 생산하는 gene 부위를 선별한 결과, 83,300 Da의 agarase(Eba1)를 생산하는 재조합 균주 E. coli BL21(DE3)/pEBA1를 얻을 수 있었다. E. coli BL21(DE3)/pEBAl에서 유도물질로 IPTG를 첨가한 후 induction 5시간 후에 agarase가 원균주에 비해 8배 증가한 양이 고발현되었다. 발현된 agarase는 Asx(Aspartic acid, Asparagine), Glycine와 같은 산성 아미노산의 함량과 Alanine과 같은 중성 아미노산의 함량이 높았으며, pH 5.6, $40^{\circ}C$에서 최적의 활성을 나타내었다. 최적 기질 agar에 대한 $K_m$과 $V_{max}$값은 0.068 mg/$m{\ell}$과 0.094mg/$m{\ell}{\cdot}min$으로 한천의 ${\beta}$-결합을 자르는 ${\beta}$-agarase로 판명되었다.

• 한국농공학회논문집
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• 제60권3호
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• pp.15-25
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• 2018

Estimating the reference evapotranspiration is an important factor to consider in irrigation system design and agricultural water use. However, there is a limitation in using the FAO Penman-Monteith (FAO P-M) equation, which requires various meteorological data. The purpose of this study is to compare three reference evapotranspiration (ETo) equations in the case of meteorological data missing for 11 study weather stations. Firstly, the FAO P-M equation is used for reference potential evapotranspiration estimation with the actual solar radiation data $R_n$ and the actual vapor pressure $e_a$. Then, in the case of $R_n$, and $e_a$ are missed, the reference evapotranspirations applying FAO P-M, Priestley-Taylor (P-T), Hargreaves (HG) equation were calculated using other meteorological factors. Secondly, MAE, RMSE, $R^2$ were calculated to compare ETo relationship from the ETo equations. From the results, ETo with Hargreaves equation in coastal areas and the Priestley-Taylor equation in the inland areas showed relatively high correlation with FAO P-M when $e_a$ data is missed. In the case of $R_n$ data is missed or two weather data, $e_a$, and $R_n$ data are all missed, $R^2$ value in Priestley-Taylor equation was highest in coastal areas, and $R^2$ values in Hargreaves equation were the high values for 7 inland areas. The results of sensitivity analysis showed that net radiation was the most sensitive for P-T and HG equation, and for FAO P-M, the most sensitive factor was net radiation and relative humidity, air temperature and wind speed were follows. Therefore, in considering of the accessibility to the coast, the types of the missing wether data, and the correlation and the magnitude of error, the reference evapotranspiration equations would be selected in sense of different conditions.

• 한국미생물·생명공학회지
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• 제51권1호
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• pp.37-42
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• 2023

Neutral and non-essential amino acid, glutamine (Gln), plays an essential role in supplying nitrogen to all the amino acids and nucleotides in the mammalian body. Gln is also the most important carbon source that provides intermediates for gluconeogenesis and fatty acid synthesis and supplements the tricarboxylic acid cycle in fast-growing cancer cells. Among the known 14 Gln transporter genes, soluted carrier family 1 member 5 (SLC1A5) has been reported to be closely associated with cancer cell growth. Three variants (v1, v2, and v3) have been derived from SLC1A5. Here, we established a heterologous gene expression system for the active form of human SLC1A5 variant-2 (hSLC1A5v2) in Escherichia coli. v2 is the smallest variant that has not yet been studied. Four expression systems were investigated: pBAD, pCold, pET, and pQE. We also addressed the problem of codon usage bias. Although pCold and pET overexpressed hSLC1A5v2 in E. coli, they were functionally inactive. hSLC1A5v2 using the pBAD system was able to catalyze the successful transport of Gln, even if it was not highly expressed. Initial activity of hSLC1A5v2 for [¹⁴C] Gln uptake in E. coli reached up to 6.73 μmole·min^-1·gDW^-1 when the cell was induced with 80 mM L-arabinose. In this study, we demonstrated a heterologous expression system for the human membrane protein, SLC1A5, in E. coli. Our results can be used for the functional comparison of SLC1A5 variants (v1, v2, and v3) in future studies, to facilitae the developement of SLC1A5 inhibitors as effective anticancer drugs.

• Carbon letters
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• 제13권3호
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• pp.173-177
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• 2012

A drug delivery system (DDS) was prepared with a temperature and pH-responsive hydrogel. Poly(vinyl alcohol) (PVA)/poly(acrylic acid) (PAAc)/poly(N-isopropylacrylamide) (PNIPAAm)/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared by radical polymerization for the temperature and pH-responsive hydrogels. MWCNTs were employed to improve both the thermal conductivity and mechanical properties of the PVA/PAAc/PNIPAAm/MWCNT nanocomposite hydrogels. Various amounts of MWCNTs (0, 0.5, 1 and 3 wt%) were added to the nanocomposite hydrogels. PVA/PAAc/PNIPAAm/MWCNT nanocomposite hydrogels were characterized with a scanning electron microscope. The mechanical properties were measured with a universal testing machine. Swelling and releasing properties of nanocomposite hydrogels were investigated at various temperatures and pHs. Temperature and pH-responsive release behavior was found to be dependent on the content of MWCNTs in nanocomposite hydrogels.

• Journal of Microbiology
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• 제40권2호
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• pp.125-128
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• 2002

The aerobic respiratory chain of Vibrio alginolyticus possesses two different kinds of NADH oxidase systems, i.e., an $Na^{+}$-dependent NADH oxidase system and an $Na^{+}$-independent NADH oxidase system. When deamino-NADH, which is the only substrate for the $Na^{+}$-dependent NADH oxidase system, was used as a substrate, the maximum activities of $N^{+}$-dependent NADH: quinone oxidoreductase and $Na^{+}$-dependent NADH oxidase were obtained at about 0.06 M and 0.2 M NaCl, respectively. When NADH, which is a substrate for both $Na^{+}$-dependent and $Na^{+}$-independent NADH oxidase systems was used as a substrate, the NADH oxidase activity had a pH optimum at about 8.0. In cGntrastl when deamino-NADH was used as a substrate, the NADH oxidase activity had a pH optimum at about 9.0. On the other handle inside-out membrane vesicles prepared from the wild-type bacterium generated only a very small $\Delta$pH by the NADH oxidase system, whereas inside-out membrane vesicles prepared from Napl, which is a mutant defective in the $Na^{+}$ pump, generated $\Delta$pH to a considerable extent by the NADH oxidase system. On the basis of the results\ulcorner it was concluded that the respiratory chain-linked components of V. atginotyticus affect each other.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2018년도 공동국제학술발표회
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• pp.194-194
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• 2018

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.550-557
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• 2010

Escherichia coli (E. coli) heat-labile enterotoxin B subunit (LTB) was regarded as one of the most powerful mucosal immunoadjuvants eliciting strong immunoresponse to coadministered antigens. In the research, the high-level secretory expression of functional LTB was achieved in P. pastoris through high-density fermentation in a 5-1 fermentor. Meanwhile, the protein was expressed in E. coli by the way of inclusion body, although the gene was cloned from E. coli. Some positive yeast and E. coli transformants were obtained respectively by a series of screenings and identifications. Fusion proteins LTB-6$\times$His could be secreted into the supernatant of the medium after the recombinant P. pastoris was induced by 0.5% (v/v) methanol at $30^{\circ}C$, whereas E. coli transformants expressed target protein in inclusion body after being induced by 1 mM IPTG at $37^{\circ}C$. The expression level increased dramatically to 250-300 mg/l supernatant of fermentation in the former and 80-100 mg/l in the latter. The LTB-6$\times$His were purified to 95% purity by affinity chromatography and characterized by SDS-PAGE and Western blot. Adjuvant activity of target protein was analyzed by binding ability with GMI gangliosides. The MW of LTB-6$\times$His expressed in P. pastoris was greater than that in E. coli, which was equal to the expected 11 kDa, possibly resulted from glycosylation by P. pastoris that would enhance the immunogenicity of co-administered antigens. These data demonstrated that P. pastoris producing heterologous LTB has significant advantages in higher expression level and in adjuvant activity compared with the homologous E. coli system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1123-1125
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• 2005

본 논문에서는 3차원 공간에 종이와 같은 박막형 유전체가 있을 때 임의의 점에서의 전계$\vec{E}$를 구하기 위해 유전체의 분극벡터$\vec{P}$를 미지수로 하는 경계적분법(Boundary integral method)을 사용한다. 경계적분법의 사용으로 FEM 3차원 해석에 있어서의 요소분할의 난이성 및 계수 행렬의 대형화로 인한 컴퓨터 수행능력의 한계를 극복할 수 있다. 여기서 분극벡터$\vec{P}$를 구하기 위해 전하에서의 전계${ves{E}}_s$에 의한 유전체내의 분극벡터$\vec{P}$를 수식으로 정리하여 $[\vec{K}][\vec{P}]=[\vec{E}]$ 형태의 $\vec{P}$를 미지수로 하는 system matrix를 구성한다. 위의 system matrix 통해 구해진 분극벡터 $\vec{P}$를 이용하여 유전체 밖의 한 점에서의 전계세기 ${\vec{E}}_m$를 구한 후 우리가 구하고자 하는 전계$\vec{E}$를 계산한다.

• 대한수의학회지
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• 제40권2호
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• pp.403-414
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• 2000

To improve the semen production, the selenium(Se) and vitamin E(Vit. E) were administrated into Hanwoo young sire for intensification an antioxidant system and the taurine were supplemented into semen extender for improving the semen characteristics. The 16 heads ranging from twenty to thirty two months of age were randomly assigned to control group, Se-admistrated group(Se-group), Vit. E-administrated group(Vit. E-Group) and Se and Vit. E administrated group(Se and Vit. E-group). Se and Vit. E dministrated 3 times every 30 days by intramuscular injection. The administration of Se, Vit. E, and Se and Vit. E didn't affect on semen volume, sperm concentration, and total sperm number among all groups(p>0.05). Adiministration of Se improved sperm motility and viability. Motility of Se-group and control were 26.01% and 19.20%, respectively(p<0.05). Viability of Se-group(47.07%) was higher than control group(35.73%), Vit. E group(36.55%)(p<0.05). The administration of Se and Vit. E didn't affect sperm capacitation and acrosome reaction. The 100mM taurine supplement into semen extender increased the motility of frozen/thawed semen in the Vit. E-group(p<0.05) and had a beneficial effects on decreasing abnormality of frozen/thawed semen in all groups(p<0.05). These results indicate that Se administration improve sperm motility and viability, and the taurine supplement into semen extender decrease abnormality in Hanwoo young sire.