• ALGAE
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• 제17권2호
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• pp.105-115
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• 2002

Influences of vrious environmental factors on the eutrophication of Nakdong River were analyzed statistically using water samples collected from 1 January, 1999, to 30 September, 2001 at Namji area. The relationships between the concentration of chlorophyll α (eutrophication index) and environmental factors and were analyzed to develop a statistical model which can predict the status of eutrophication. The concentation of chlorophyll α ranged from 66.2 mg · $m^{-3}$ to 70.8 mg · $m^{-3}$ during dry winter season and the average concentration during this study period was 35.5 mg · $m^{-3}$ Namji area of Nakdong River was in the hypereutrohic stage in terms of water quality. Stephanodiscus sp. and Aulacoseria granulata var. angustissima were dominant species during the witnter to spring time and summer to autumn period, respectively. Based on the correlation analysis and the analysis of variance between chlorophyll α concentration and environmental factors, significantly high positive relationships were found in the order of BOD> pH> COD > KMnO₄ consumption > DO > conductivity > alkalinity. In contrast to these factors, significantly negrative relationships were found as in the order of $PO₄^{3-}-P$ >water level>the rate of Namgang-dam discharge > NH₃-N> the rate of Andong-dam discharge> the rate of Hapchoen-dam discharge. Based on the factors analysis of environmental factors on the concentration of chlorophyll α, we obtained five factors as follows. The first factor included water level, pH, turbiditiy, conductivity, alkalinity and the rate of Namgang-dam discharge. The second factor included water temperature DO, NH₄+-N, NO₃- -N. The third factor included KMnO₄ consumption COD and BOD. The fourth factor included the rate of Andong-dam discharge, the rate of Hapcheon-dam discharge, and the rate of Imha-dam discharge. The final factor included T-N T-P and $PO₄^{3-}-P$ > concentration. We derived two statistica models that can predict the occurrence of eutrophication based on the factors by factor analysis, using regression analysis. The first model is the stepwise regression model whose independent variables are the factors produced by factor analysis : chl α (mg · $m^{-3}$ = 42.923+(18.637 factor 3) + (-17.147 factor 1) + (-12.095 factor 5) + (-4.828 factor 4). The second model is the alternative stepwise regression model whose independent variables are the sums of the standardized main component variables:chl α (mg · $m^{-3}$ = 37.295+(7.326 Zfactor 3) + (-2.704 Zfactor 1)+(-2.341 Zfactor 5).

• BMB Reports
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• 제40권3호
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• pp.315-324
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• 2007

The novel $\alpha$-amylase purified from locally isolated strain, Bacillus sp. KR-8104, (KRA) (Enzyme Microb Technol; 2005; 36: 666-671) is active in a wide range of pH. The enzyme maximum activity is at pH 4.0 and it retains 90% of activity at pH 3.5. The irreversible thermoinactivation patterns of KRA and the enzyme activity are not changed in the presence and absence of $Ca^{2+}$ and EDTA. Therefore, KRA acts as a $Ca^{2+}$-independent enzyme. Based on circular dichroism (CD) data from thermal unfolding of the enzyme recorded at 222 nm, addition of $Ca^{2+}$ and EDTA similar to its irreversible thermoinactivation, does not influence the thermal denaturation of the enzyme and its Tm. The amino acid sequence of KRA was obtained from the nucleotide sequencing of PCR products of encoding gene. The deduced amino acid sequence of the enzyme revealed a very high sequence homology to Bacillus amyloliquefaciens (BAA) (85% identity, 90% similarity) and Bacillus licheniformis $\alpha$-amylases (BLA) (81% identity, 88% similarity). To elucidate and understand these characteristics of the $\alpha$-amylase, a model of 3D structure of KRA was constructed using the crystal structure of the mutant of BLA as the platform and refined with a molecular dynamics (MD) simulation program. Interestingly enough, there is only one amino acid substitution for KRA in comparison with BLA and BAA in the region involved in the calcium-binding sites. On the other hand, there are many amino acid differences between BLA and KRA at the interface of A and B domains and around the metal triad and active site area. These alterations could have a role in stabilizing the native structure of the loop in the active site cleft and maintenance and stabilization of the putative metal triad-binding site. The amino acid differences at the active site cleft and around the catalytic residues might affect their pKa values and consequently shift its pH profile. In addition, the intrinsic fluorescence intensity of the enzyme at 350 nm does not show considerable change at pH 3.5-7.0.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.623-629
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• 2016

(1S,2S,3E,7E,11E)-3,7,11,15-cembratetraen-17,2-olide (LS-1), a marine cembrenolide diterpene, has anticancer activity against colon cancer cells such as HT-29, SNU-C5/5-FU (fluorouracil-resistant SNU-C5) and SNU-C5. However, the action mechanism of LS-1 on SNU-C5 human colon cancer cells has not been fully elucidated. In this study, we investigated whether the anticancer effect of LS-1could result from apoptosis via the modulation of $Wnt/{\beta}$-catenin and the TGF-${\beta}$ pathways. When treated with the LS-1, we could observe the apoptotic characteristics such as apoptotic bodies and the increase of sub-G1 hypodiploid cell population, increase of Bax level, decrease of Bcl-2 expression, cleavage of procaspase-3 and cleavage of poly (ADP-ribose) polymerase in SNU-C5 cells. Furthermore, the apoptosis induction of SNU-C5 cells upon LS-1 treatment was also accompanied by the down-regulation of $Wnt/{\beta}$-catenin signaling pathway via the decrease of GSK-$3{\beta}$ phosphorylation followed by the decrease of ${\beta}$-catenin level. In addition, the LS-1 induced the activation of TGF-${\beta}$ signaling pathway with the decrease of carcinoembryonic antigen which leads to decrease of c-Myc, an oncoprotein. These data suggest that the LS-1 could induce the apoptosis via the down-regulation of $Wnt/{\beta}$-catenin pathway and the activation of TGF-${\beta}$ pathway in SNU-C5 human colon cancer cells. The results support that the LS-1 might have potential for the treatment of human colon cancer.

• Biomolecules & Therapeutics
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• 제25권4호
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• pp.417-426
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• 2017

4-O-methylhonokiol, a neolignan compound from Magnolia Officinalis, has been reported to have various biological activities including hair growth promoting effect. However, although transforming growth factor-${\beta}$ (TGF-${\beta}$) signal pathway has an essential role in the regression induction of hair growth, the effect of 4-O-methylhonokiol on the TGF-${\beta}$ signal pathway has not yet been elucidated. We thus examined the effect of 4-O-methylhonokiol on TGF-${\beta}$-induced canonical and noncanonical pathways in HaCaT human keratinocytes. When HaCaT cells were pretreated with 4-O-methylhonokiol, TGF-${\beta}1$-induced G1/G0 phase arrest and TGF-${\beta}1$-induced p21 expression were decreased. Moreover, 4-O-methylhonokiol inhibited nuclear translocation of Smad2/3, Smad4 and Sp1 in TGF-${\beta}1$-induced canonical pathway. We observed that ERK phosphorylation by TGF-${\beta}1$ was significantly attenuated by treatment with 4-O-methylhonokiol. 4-O-methylhonokiol inhibited TGF-${\beta}1$-induced reactive oxygen species (ROS) production and reduced the increase of NADPH oxidase 4 (NOX4) mRNA level in TGF-${\beta}1$-induced noncanonical pathway. These results indicate that 4-O-methylhonokiol could inhibit TGF-${\beta}1$-induced cell cycle arrest through inhibition of canonical and noncanonical pathways in human keratinocyte HaCaT cell and that 4-O-methylhonokiol might have protective action on TGF-${\beta}1$-induced cell cycle arrest.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.497-502
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• 2016

To know the infection status of zoonotic trematode metacercariae in brackish water fish, we surveyed mullets collected from 18 coastal areas in the Republic of Korea. The metacercariae of Pygidiopsis summa were detected in 236 (68.2%) out of 346 mullets examined. They were found in mullets from 15 areas except for those from Boseong-gun (Jeollanam-do), Pohang-si, and Uljin-gun (Gyeongsangbuk-do). Especially in mullets from Taean-gun (Chungcheongnam-do) and Geoje-si (Gyeongsangnam-do), their prevalences were 100% and 95.5%, and the average metacercarial density was more than 1,000 per fish. They were also detected in mullets from 3 coastal lakes, Gyeongpoho, Songjiho, and Hwajinpoho, in Gangwon-do, and their average densities were 419, 147, and 672 per infected fish, respectively. The metacercariae of 5 other heterophyid species, including Heterophyes nocens, Heterophyopsis continua, Metagonimus sp., Stictodora fuscata, and Stictodora lari, were found in the mullets examined. The metacercariae of H. nocens were detected in 66.7, 100, 28.6, 81.6, 3.9, 61.5, and 27.3% of mullets from Muan-gun, Shinan-gun, Haenam-gun, Gangjin-gun, and Boseong-gun (Jeollanam-do), Hadong-gun, and Geoje-si (Gyeongsangnam-do), and their metacercarial intensities were 64, 84, 119, 99, 1, 24, and 24 per fish infected, respectively. From the above results, it has been confirmed that P. summa metacercariae are heavily infected in mullets from coastal areas of Korea. It is suggested that residents who frequently consume raw mullet dish can be easily infected with heterophyid flukes.

• Parasites, Hosts and Diseases
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• 제51권5호
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• pp.511-517
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• 2013

Species identification using DNA sequences is the basis for DNA taxonomy. In this study, we sequenced the ribosomal large-subunit RNA gene sequences (3,037-3,061 bp) in length of 13 Chinese Theileria stocks that were infective to cattle and sheep. The complete 28S rRNA gene is relatively difficult to amplify and its conserved region is not important for phylogenetic study. Therefore, we selected the D2-D3 region from the complete 28S rRNA sequences for phylogenetic analysis. Our analyses of 28S rRNA gene sequences showed that the 28S rRNA was useful as a phylogenetic marker for analyzing the relationships among Theileria spp. in ruminants. In addition, the D2-D3 region was a short segment that could be used instead of the whole 28S rRNA sequence during the phylogenetic analysis of Theileria, and it may be an ideal DNA barcode.

• 한국버섯학회지
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• 제13권4호
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• pp.326-329
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• 2015

영지버섯과 상황버섯의 항당뇨 효능을 알아보기 위하여 실험을 수행하였으며, 당뇨병에 negative regulator로 작용하는 PTP1B의 억제 활성을 살펴본 결과 영지버섯과 상황버섯이 억제 활성을 보였으며, 타액의 ${\alpha}-amylase$는 타액과 췌장내에서 탄수화물의 소화에 있어서 중요한 효소로 작용하며 이 효소를 저해시킴으로서 탄수화물의 소화 속도를 지연시켜 식후 혈당 상승을 억제할 수 있다. ${\alpha}-amylase$ 억제활성정도를 실험으로 확인한 결과 양성대조구와 비슷한 억제활성을 보였으며, 상황버섯은 89%로 Acarbose와 같은 억제 활성을 보였다. ${\alpha}-glucosidase$는 다당류의 탄수화물을 단당류로 분해하는 탄수화물의 소화와 흡수에 필수적인 효소로 억제활성을 실험으로 확인한 결과 양성대조구와는 다르게 낮은 억제 활성을 보였다. 두 가지 소화효소에 모두 억제활성을 보이는 기존제품의 단점을 보완할 수 있을 것으로 생각된다.

• 한국버섯학회지
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• 제13권4호
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• pp.305-309
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• 2015

Cellulase와 xylanase 분비능이 우수한 부숙촉진 세균을 분리하기 위하여 진주시 집현면 소재의 느타리버섯 재배농장으로부터 느타리버섯 수확후배지를 수집하였다. 느타리버섯 수확후배지로부터 19종의 균주를 분리하였으며 이 중 cellulase와 xylanase을 동시에 분비하는 균주를 최종 선발하여 CA105로 명명하였다. Bacillus ID kit와 VITEK 2 system를 이용하여 분리균 CA105의 생화학적 특성을 조사한 결과에서도 분리균 CA105은 B. subtilis와 유사한 특징을 나타내었으며 16S rRNA 염기서열 분석 결과에서는 B. subtilis와 98.9%의 상동성을 나타내었다. 이와 같은 결과를 종합하여 분리균 CA105은 Bacillus subtilis CA105로 동정되었다. 분리균이 분비하는 cellulase와 xylanase 활성은 분리균이 증식함에 따라 대수증식기 중반부터 급격히 증가하였고 정지기에 진입하면 효소활성이 더 이상 증가하지 않는 것으로 나타났다.

• 생명과학회지
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• 제15권1호
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• pp.55-60
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• 2005

생쥐의 도파민 수용체 조절인자 (DRRF)유전자는 몇몇 Spl 결합부위를 가지고 TATA가 없는 프로모터로부터 전사된다. 본 연구에서는 이 유전자의 발현을 조절하는 기능성 조절인자들을 밝힌다. $D_2$ 도파민 수용체를 발현하는 NB41A3 세포에서 Spl은 pCAT-DRRF-l153/+17에 포함된 DRRF 프로모터부터 의 전사를 촉진시키지만 DRRF는 전사를 억제시켰다. -1153과 -1122 사이의 31 bp 단편의 결손에 의해 전사활성은 약 $60\%$ 정도 감소하였다. 이 단편은 기능성 AP1 결합부위를 포함하고 있다 게다가, -901과 -772사이의 129 bp영역의 결손에 의해 전사활성이 더욱 더 감소하였다. 이 영역은 기능성 AP2 결합부위를 가진다. DRRF_AP1 (bases -1153 to -1121) 탐침을 이용한 gel shift실험에서 특정 벤드가 관찰되었고, 이 벤드는 API 상보성 경쟁자에 의해 효과적으로 사라졌다. 더욱이, DRRF_AP2 (bases -873 to -846) 탐침을 이용한 gel shift실험에서도 특정 벤드가 관찰되었고, 이 벤드도 AP2상보성 경쟁자에 의해 효과적으로 사라졌다. 본 연구결과로, Spl과 DRRF가 DRRF 프로모터를 효과적으로 조절한다는 사실과, AP1과 AP2 역시 이 유전자를 조절한다는 사실을 알 수 있었다.

• 생명과학회지
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• 제25권11호
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• pp.1319-1323
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• 2015

매년 어류 양식의 생산량은 증대되고 있으며, 생산량 증가를 위한 고밀도 사육은 수질 악화 및 어류들의 스트레스를 증가시켜 질병들이 잦아지게 된다. 이로 인한 경제적 피해는 어류 양식 어민들에게 있어 막대한 피해를 입게 되며, 이를 예방하기 위해 화학 요법인 항생제를 투여하게 된다. 본 연구에서는 항생제 대체 물질 및 안전 요법으로 알려진 프로바이오틱스를 분리하기 위해, 한국전통식품인 고추 장아찌와 갈치 젓갈에서 다양한 세균을 분리하였다. 분리 된 균주들은 16S rDNA 염기서열을 분석 및 동정하고, 상층액 및 균체로 나뉘어 항균 활성을 측정하였다. 고추 장아찌에서 분리된 4종과 갈치 젓갈에서 분리된 7종은 상층액 보다 균체에서 항균 활성이 높게 나타나는 것을 확인할 수 있었다. 그 중 JKM-2는 43 mm(S. iniae), 40 mm(S. parauberis), 35 mm(S. mutans), 26.5 mm(V. vuinificus)로 가장 높은 항균 활성을 나타냈다. 본 균주의 염기서열 분석 결과, Bacillus subtilis 97.71%, Bacillus tequilensis 97.71%, Brevibacterium halotolerans 97.71%, Bacilus subtils 97.63%, Bacillus subtlis 97.63%, Bacillus mojavensis 97.54%, Bacillus vallismortis 97.46%, Bacillus nanillea 97.45%, Bacillu smethylotrophicus 97.37%, Bacillu ssiamensis 97.37%로 분석되었다. 추후 JKM-3의 신종 균주 확인과 균체 물질 규명 및 분석을 통하여 충분한 안정성을 확보하고 양식 산업에 적용시켜 항생제 대체 물질로서의 이용가치를 확인하고자 한다.