유독성 와편모류 Alexandrium catenella에 대한 Pseudoalteromonas sp. NH-12의 살조능

정남호 ( Nam Ho Jeoung ),손홍주 ( Hong Joo Son ),정성윤 ( Seong Yun Jeong ) 한국환경농학회 2012 한국환경농학회지 Vol.31 No.2

우리나라뿐만 아니라 전 세계적으로 적조 및 마비성 패독을 일으켜 문제시되고 있는 유독성 와편모류인 A. catenella를 살조시키는 해양미생물 Pseudoalteromonas sp. NH-12를 마산만의 적조발생 해역에서 분리, 동정하고 그 특성과 살조능에 대해 연구함으로써 보다 환경 친화적인 적조 구제 기술개발의 기초 자료를 제공하고자 하였다. 적조발생 해역인 마산만의 해수에서 분리한 38개의 해양미생물 균주 중 4종의 미생물이 A. catenella에 대해 살조능을 나타내었으며, 이중 살조능이 가장 우수한 NH-12 균주를 선별하였다. 본 균주는 API kits 및 16S rRNA gene 염기서열을 분석하여 계통분류를 행한 결과 Pseudoalteromonas 속으로 분류되었으며, 최적 배양조건은 25℃, pH 8.0, 3.0% NaCl 농도였다, Pseudoalteromonas sp, NH-12의 성장 단계별 살조능은 대수증식기 후기, 정지기, 대수증식기 중기, 유도기순으로 높게 나타났다. 살조물질은 대수증식기 중기 이후에 활발히 생산되기 시작하여 대수증식기 후기에 가장 고농도로 축적되는 것으로 판단된다. 2조 배양계를 이용한 살조 유형조사에서 Pseudoalteromonas sp. NH-12는 격리된 상태에서도 A. catenella를 살조시켜 ``직접 공격형``이 아니라 세포외로 물질을 분비하여 살조시키는 ``살조인자 분비형``으로 확인되었다. 또한 NH-12 균주 배양여과액을 5% 첨가하였을 때 36시간 후에 A. catenella는 100% 살조되었고, 10%를 첨가한 경우 24시간 후에 99% 이상 살조되었다. BACKGROUND: The aim of this study was to isolate and identify algicidal bacterium that tends to kill the toxic dinoflagellate Alexandrium catenella, and to determine the algicidal activity. METHODS AND RESULTS: Among of four algicidal bacteria isolated in this study, NH-12 isolate was the strongest algicidal activity against A. catenella. NH-12 isolate was identified on the basis of biochemical characteristics and analysis of 16S rRNA gene sequences. The isolate showed 97.67% homology with Pseudoalteromonas prydzensis ACAM 620T (U85855), and was designated Pseudoalteromonas sp. NH-12. The optimal culture conditions of this isolate were 25℃, initial pH 8.0, and 3.0% (w/v) NaCl concentration. The algicidal activity of NH-12 was significantly increased to maximum value in the late of logarithmic phase of bacterial culture. As a result of ``cell culture insert`` experiment, NH-12 is assumed to produce secondary metabolites, as an indirect attacker. When 10% culture filtrate of NH-12 was applied to A. catenella, over 99% of algal cells were destroyed within 24 h. In addition, the killing effects were increased in dose and time dependent manners. CONCLUSION(S): Taken together, our results suggest that Pseudoalteromonas sp. NH-12 could be a candidate for controlling of toxic algal blooms.

CETP 의 CE Transfer 기능과 측정방법

박용복,정남호,김홍석,최명숙 ( Yong Bok Park,Nam Ho Jeoung,Hong Seok Kim,Myung Sook Choi ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.5

Cholesteryl ester (CE) transfer between lipoproteins was studied in vitro in various incubation mixtures containing isolated lipoproteins and an inhibitor of lecithin: cholesterol acyltransferase (LCAT). Isolated high-density lipoproteins (HDL) exhibited a significant amount of cholesteryl ester transfer activity. In incubations of HDL with very low-density lipoproteins (VLDL) at 37℃, decrease of free cholesterol (FC) in human VLDL was mainly associated with decrease of cholesteryl ester (CE) in HDL. In this system, FC of human VLDL was transferred to human HDL, but could not be esterified due to LCAT inhibitor resulting in an accumulation of FC in HDL fraction. However, CE in human HDL was transferred to human VLDL during the incubation. This appears to be the major mean for keeping cholesterol equilibrium between lipoproteins. Another results support that cholesteryl ester transfer protein (CETP) promotes both the exchange and net transfer of cholesterol species between lipoproteins and that the net transfer proceeds in the direction of HDL to lower density lipoproteins, which are well agreed with the previous reports. In efforts to simplify the CETP assay method, cholesteryl-[^(14)C]-oleate in reconstituted HDL (R_(HDL)) covalently bound to agarose beads was used as a CE donor. This simple evaluation of CE transfer activity did not require the time-consuming ultracentrifugation before and after the incubation, that has been used in the previous assay. It also eliminates the use of heparine-MnC1₂ or dextran sulfate-MgC1₂ for the precipitation of LDL or VLDL, that is relatively costly.

Alexandrium catenella와 유해성 적조종에 대한 Arthrobacter sp. NH-3와 살조물질의 살조능

정성윤 ( Seong Yun Jeong ),정남호 ( Nam Ho Jeoung ) 한국환경농학회 2015 한국환경농학회지 Vol.34 No.2

BACKGROUND: The aim of this study was to isolate and identify algicidal bacterium that tends to kill the toxic dinoflagellate Alexandrium catenella, and to determine the algicidal activity and algicidal range of algicide. METHODS AND RESULTS: Among of algicidal bacteria isolated in this study, NH-3 isolate was the strongest algicidal activity against A. catenella. NH-3 isolate was identified on the basis of biochemical characteristics and analysis of 16S rRNA gene sequences. The NH-3 isolate showed over 99% homology with Arthrobacter oxydans, and was designated as Arthrobacter sp. NH-3. The optimal culture conditions were 25℃, initial pH 7.0, and 2.0% (w/v) NaCl concentration. The algicidal activity of Arthrobacter sp. NH-3 was significantly increased to maximum value in the late of logarithmic phase. Arthrobacter sp. NH-3 showed algicidal activity through indirect attack, which excreted active substance into the culture filtrate. When 10% culture filtrate of NH-3 was applied to A. catenella, 100% of algal cells were destroyed within 30 h. In addition, the algicidal activities were increased in dose and time dependent manners. The pure algicide was isolated from the ethyl acetate extract of the culture filtrate of NH-3 by using silica gel column chromatography and high performance liquid chromatography (HPLC). We investigated the algicidal activity of this algicide on the growth of harmful algal bloom (HAB) species, including A. catenella. As a result, it showed algicidal activity against several HAB species at a concentration of 100 μg/mL and had a relatively wide host range. CONCLUSION: Taken together, our results suggest that Arthrobacter sp. NH-3 and its algicide could be a candidate for controlling of toxic and harmful algal blooms.

연구보문 : 수질환경 ; 광양만에서 TBTCl (Tributyltin Chloride) 내성세균의 분리 및 분해활성

정성윤 ( Seong Yun Jeong ),손홍주 ( Hong Joo Son ),정남호 ( Nam Ho Jeoung ) 한국환경농학회 2011 한국환경농학회지 Vol.30 No.4

BACKGROUND: Tributyltin chloride is among the most toxic compounds known for aquatic ecosystems. Microorganisms are responsible for removal of TBTCl. Nevertheless, only limited number of marine bacteria were investigated for biodegradation of TBTCl in Korea. METHODS AND RESULTS: The number of TBTCl resistant bacteria ranged from 2.5 x 10(3) to 3.8 x 10(3) cfu/mL in the seawater, and ranged from 3.2 x 10(5) to 9.1 x 10(5) cfu/g in the surface sediment, respectively. The morphological, physiological, and biochemical characteristics of TBTCl resistant bacteria were investigated by API 20NE and other tests. The most abundant species of TBTCl resistant bacteria were Vibrio spp. (19.2%), Bacillus spp. (16.2%), Aeromonas spp. (15.2%), and Pseudomonas spp. (13.1%), etc. Eleven TBTCl resistant isolates also had a resistance to heavy metals (Cd, Cu, Hg, and Zn). Among them, isolate T7 showing the strong TBTCl-resistance was selected. This isolate was identified as the genus Pantoea by 16S rRNA gene sequencing and designated as Pantoea sp. T7. In addition, this bacterium was cultivated up to the growth of 50.7% after 60 hrs at TBTCl concentration of 500 μM. TBTCl-degrading activity of Pantoea sp. T7 was measured by GC-FPD analysis. As a result of biological TBTCl-degradation at TBTCl concentration of 100 μM, TBTCl-removal efficiency of Pantoeasp. T7 was 62.7%after 40 hrs. CONCLUSION(S): These results suggest that Pantoea sp. T7 is potentially useful for the bioremediation of TBT contamination.

Differentially Expressed Aortic Genes in Cholesterol-fed Rabbits

김태균(Tae Gyun Kim),장문규(Moon Kyoo Jang),정남호(Nam Ho Jeoung),최명숙(Myung Sook Choi),복성해(Song Hae Bok),곽주운(Ju Won Kwak),박용복(Yong Bok Park) 경북대학교 생명공학연구소(구 경북대학교 유전공학연구소) 1998 遺傳工學硏究所報 Vol.13 No.1

N/A N/A

Dichloroacetate Inhibits the Proliferation of a Human Anaplastic Thyroid Cancer Cell Line via a p53-independent Pathway

Yam Bahadur KC(얌 바하더 케이씨),Sunil Poudel(수닐 포우델),Eon Ju Jeon(전언주),Ho Sang Shon(손호상),Sung June Byun(변승준),Nam Ho Jeoung(정남호) 한국생명과학회 2018 생명과학회지 Vol.28 No.12

Warburg 효과의 발생은 고형암에서 화학적 항암제의 내성을 발생시킨다. 따라서 호기성 해당과정과 같은 에너지 대사과정은 암 치료의 중요한 표적으로 알려져 있다. Pyruvate dehydrogenase kinase (PDK) 활성 억제물질로 알려진 dichloroacetate (DCA)는 많은 암세포에서 포도당의 호기성 해당과정을 산화적인산화 과정으로 전환시킬 수 있음이 보고되었다. 이 연구는 치료가 매우 어렵다고 알려진 인간 역분화 갑상선 암세포주인 8505C의 성장에 미치는 DCA효과를 조사하였다. DCA는 정상 갑상선 세포주의 성장에는 영향을 주지 않은 반면 8505C 세포주의 성장을 특이적으로 저해하였다. DCA의 처리에 의해 8505C 세포주는 HIF1α, PDK1, Bcl-2와 같은 항-세포자살 관련 단백질들의 발현이 감소하고, Bax와 p21과 같은 세포자살 유도 단백질과 세포주기 억제 단백질의 증가로 인하여 세포주기 정지와 세포자살 유도에 의해 성장이 억제되었다. 이런 세포의 변화는 DCA 처리에 의한 활성산소족의 생산이 증가하고, 포도당 대사가 호기성 해당과정에서 산화적인산화 과정으로 전환되었기 때문이란 것을 확인하였다. 흥미롭게도, DCA는 포도당 대사과정의 변화뿐만 아니라 sodium/iodine symporter (NIS)의 발현양도 증가시킨다는 것을 확인하였다. 이 연구의 결과로 PDK 활성 저해제는 치료하기 힘든 역분화 갑상선 암 치료제로 이용할 수 있고, 또한 역분화 갑상선 암에 대한 방사능 치료의 효능을 높일 수 있을 것으로 기대된다. Occurrence of the Warburg effect in solid tumors causes resistance to cancer chemotherapy, and targeting energy metabolisms such as aerobic glycolysis is a potential strategy for alternative treatment. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), shifts glucose metabolism from aerobic glycolysis to oxidative phosphorylation (OxPhos) in many cancers. In this study, we investigated the anticancer effect of DCA on a human anaplastic thyroid cancer (ATC) cell line, 8505C. We found that DCA selectively inhibits cell proliferation of the 8505C line but not of a normal thyroid line. In 8505C, the cell cycle was arrested at the G1/S phase with DCA treatment as a result of decreased antiapoptotic proteins such as HIF1α, PDK1, and Bcl-2 and increased proapoptotic proteins such as Bax and p21. DCA treatment enhanced the production of reactive oxygen species which consequently induced cell cycle arrest and apoptosis. Interestingly, DCA treatment not only reduced lactate production but also increased the expression of sodium-iodine symporter, indicating that it restores the OxPhos of glucose metabolism and the iodine metabolism of the ATC. Taken together, our findings suggest that PDK inhibitors such as DCA could be useful anticancer drugs for the treatment of ATC and may also be helpful in combination with chemotherapy and radiotherapy.

Reaction of HDL-Bound Cholesteryl Ester Transfer Protein and a New Method for Its Activity Measurement

Jeoung,Nam-Ho,Choi,Myung-Sook,Kim,Hong-Seok,Park,Yong Bok 國立 昌原大學校 基礎科學硏究所 1993 基礎科學硏究所論文集 Vol.4 No.-

간편하고 신뢰성이 높은 CE transfer activity 측정법을 개발하려는 시도에서 정제된 혈장 HDL과 합성된 HDL(RHDL)을 CE donor로써 사용하였다. 혈장 HDL은 높은 CETP활성을 보여 정제된 혈장 HDL은 HDL/CETP complex로 이루어졌다는 것을 알 수 있었다. 이 CETP는 lipoprotein들 간의 CE교환과 순이동을 촉매했으며 순이동 현상은 HDL로부터 lower density lipoprotein쪽으로 진행되었다. 그러나 본 실험에서 apolipoprotein A-Ⅰ, 인지질, 콜레스테롤, TG를 구성성분으로 하여 합성한 HDL을 agarose에 결합시켜 CE donor로 사용한 결과 지금까지 사용되어온 방법들에 비해 신뢰성이 높았고 assay 시간과 비용이 단축되었다. Cholesteryl ester (CE) transfer between lipoproteins was studied in vitro in various incubation mixtures containing isolated lipoproteins and an inhibitor of lecithin:cholesterol acyltransferase (LCAT). Isolated high-density lipoproteins (HDL) exhibited a significant amount of cholesteryl ester transfer activity. In incubations of HDL with very low-density lipoproteins (VLDL) at 37℃, decrease of free cholesterol (FC) in human VLDL was mainly associated with decrease of cholesteryl ester (CE) in HDL. In this system, FC of human VLDL was transferred to human HDL, but could not be esterified due to LCAT inhibitor resulting in an accumulation of FC in HDL fraction. However, CE in human HDL was transferred to human VLDL during the incubation. This appears to be the major mean for keeping cholesterol equilibrium between lipoproteins. Another results support that cholesteryl ester transfer protein (CETP) promotes both the exchange and net transfer of cholesterol species between lipoproteins and that the net transfer proceeds in the direction of HDL to lower density lipoproteins, which are well agreed with the previous reports. In efforts to simplify the CETP assay method, cholesteryl-[¹⁴C]-oleate in reconstituted HDL (RHDL) covalently bound to agarose beads was used as a CE donor. This simple evaluation of CE transfer activity did not require the time-consuming ultracentrifugation before and after the incubation, that has been used in the previous assay. It also eliminates the use of heparine-MnCl₂ordextran sulfate-MgCl₂for the precipitation of LDL or VLDL, that is relatively costly.

Human Cholesteryl Ester Transfer Protein ( CETP ) Gene contains a noble negative Glucocorticoid Response Element ( nGRE ) in the its proximal promoter region

박용복,정남호,Nam,Jeong Il 한국지질학회 1998 韓國脂質學會誌 Vol.8 No.1

Studies on A Hyperlipidemic Family Found in Taegu Area

박용복,정남호 한국지질학회 1993 韓國脂質學會誌 Vol.3 No.2

대구 지역에서 발견된 고지혈종 가계에 대한 연구

최명숙,박용복,정남호,채성철 한국지질학회 1993 韓國脂質學會誌 Vol.3 No.2

This study was designed to search potential causes of a hyperlipidemic family found in Taegu area. Members of the family have been found to have an abnormally high content of low density lipoprotein (LDL)-cholesterol and a large size of very low density lipoprotein (VLDL) according to the results from lipid analyses and agarose gel electrophoresis, respectively. It turned out that Lecithin: cholesterol Acyltransferase activity, content of Lp (a) and HDL-cholesterol level of these family members were normal. However, activity of cholesteryl ester transfer protein (CETP, 50∼60% of CE transfer/6 hr) were very high compared to normal persons. In the restriction fragment length polymorphism(RFLP) analyses of CETP gene by Taq I restriction enzyme, 4.6 kb, 3.8 kb and 1.4 kb bands appeared in samples from both normal persons and hyperlipidemic patients. On the other hand, 2.5 kb and 0.8 kb bands which were found only in normal people and ischemic heart disease patients were not shown in the hyperlipidemic family. In the RFLP analyses of apo-E gene by Hha I, there were significant differences in the band patterns between the control groups and the hyperlipidemic subjects. In the RFLP analyses of apo-B gene by Msp I, normal persons showed a consistent 2.2 kb band and a polymorphism at 0.7, 0.5, 0.4 and 0.1 kb, while some of hyperlipidemic family members had 9.4 kb band. In RFLP pattern of EcoR I restriction enzyme digestion, the normal and hyper-lipidemic family groups showed considerably different patterns. In conclusion, blood cholesterol of this family seems to be rapidly transferred from HDL to VLDL or LDL due to the high CETP activity. The transferred cholesterol appears to be improperly cleared from the blood stream presumably by the abnormal apo-B and apo-E.