• 한국균학회지
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• 제12권1호
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• pp.1-8
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• 1984

1. Benomyl은 버섯류(類)의 균사생장(菌絲生長)을 억제(抑制)하였는데 $ED_{50}$은 Pleurotus spp. 25ppm, Agaricus bisporus 50ppm, Flammulina velutipes 200ppm으로서 Pleurotus spp.가 benomyl에 대하여 감수성(感受性)이 가장 높았다. 2. Benomyl 함유배지(含有培地)에서 계대배양(繼代培養)할 때 5세대(世代) 및 10세대(世代)에는 1세대(世代)보다 균사생장(菌絲生長)이 증가(增加)하였고 생장증가율(生長增加率)은 명(各) 버섯균(菌)의 benomyl $ED_{50}$농도(濃度)에서 가장 높았다. 3. Benomyl 처리(處理) 배지(培地)에서의 계대별(繼代別) 균사생장(菌絲生長)은 균(菌)의 종류(種類)에 따라 달라서 P. florida는 5세대(世代), Agricus bisporus는 7대(代)까지는 균사생장(菌絲生長)이 증가(增加)하다가 그후 감소(減少)하는 경향(傾向)이었다. 4. Benomyl의 계속처리(繼續處理)는 mutant sector의 발생(發生)을 유기(誘起)하였는데 sector의 출현(出現)은 benomyl의 처리농도(處理濃度)가 낮을때 빨랐으며 P. ostreatus가 P. florida 보다 빨랐다. 5. Benomyl에 의해 유기(誘起)된 mutant sector는 약제(藥劑)에 계속처리(繼續處理)된 모(母) colony 보다 균사생장(菌絲生長)이 빨랐으나 benomyl에 대한 저항성(抵抗性)에는 차이(差異)가 없었다. benomyl란 함유배지(含有培地)에서 계대배양시(繼代培養時) 정상(正常) colony에서 보인 균사생장(菌絲生長)의 증가(增加)는 약제저항성(藥劑抵抗性)에 기인(起因)하는 것이었다.

• Applied Biological Chemistry
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• 제4권
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• pp.11-16
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• 1963

Penicillium균(菌) 30주(株) Aspergillus균(菌) 52주(株)의 5'-Phosphodiesterase activity를 screen하여 강력(强力)한 Penicillium sclerotiorum 6321, Penicillium SP M-11 그리고 Penicillium citrinum UV-mutant 2032-72 선발(選拔)하였다. (2) 밀기울 배지(培地)호 $30^{\circ}C$ 10일(日)의 정치배양(靜置培養)에서 5‘-Phosphodiesterase생산(生産)이 강(强)했다. (2) Penicillium sclerotiorum 7321가 Penicillium SP M-11의 5‘-Phosphodiesterase 최적조건(最適條件)이 pH 4.0, $62.^{\circ}C$이고 Penicillium citrinum UV-mutant 2032-72 의 5'-Phosphodiesterase 최적조건(最適條件)은 PH5.0, $50^{\circ}C$이다.

• Biomolecules & Therapeutics
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• 제21권2호
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• pp.114-120
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• 2013

Most patients with mutant B-Raf melanomas respond to inhibitors of oncogenic B-Raf but resistance eventually emerges. To better understand the mechanisms that determine the long-term responses of mutant B-Raf melanoma cells to B-Raf inhibitor, we used chronic selection to establish B-Raf (V600E) melanoma clones with acquired resistance to the new oncogenic B-Raf inhibitor UI-152. Whereas the parental A375P cells were highly sensitive to UI-152 ($IC_{50}$ < $0.5{\mu}M$), the resistant sub-line (A375P/Mdr) displayed strong resistance to UI-152 ($IC_{50}$ < $20{\mu}M$). Immunofluorescence analysis indicated the absence of an increase in the levels of P-glycoprotein multidrug resistance (MDR) transporter in A375P/Mdr cells, suggesting that resistance was not attributable to P-glycoprotein overexpression. In UI-152-sensitive A375P cells, the anti-proliferative activity of UI-152 appeared to be due to cell-cycle arrest at $G_0/G_1$ with the induction of apoptosis. However, we found that A375P/Mdr cells were resistant to the apoptosis induced by UI-152. Interestingly, UI-152 preferentially induced autophagy in A375P/Mdr cells but not in A375P cells, as determined by GFP-LC3 puncta/cell counts. Further, autophagy inhibition with 3-methyladenine (3-MA) partially augmented growth inhibition of A375P/Mdr cells by UI-152, which implies that a high level of autophagy may protect UI-152-treated cells from undergoing growth inhibition. Together, our data implicate high rates of autophagy as a key mechanism of acquired resistance to the oncogenic B-Raf inhibitor, in support of clinical studies in which combination therapy with autophagy targeted drugs is being designed to overcome resistance.

• 한국환경농학회지
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• 제25권2호
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• pp.124-128
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• 2006

황 화합물 악취를 제거하기 위하여 UV-B를 돌연변이원으로 처리한 후 공시균주 Thiobacillus sp. IW보다 성장속도가 빠른 변이주 UIW-6를 분리하여 최적성장 조건을 조사하였다. 변이주 UIW-6의 특성을 조사한 결과 최적조건은 pH 6.5, 배양온도는 $35^{\circ}C$이었으며, 회전속도는 200 rpm 이었다. 황 화합물인 sodium thiosulfate 농도가 50 mM에서 변이주 UIW-6는 6시간째에 공시균주 IW보다 성장정도가 2배 더 빨랐다. 변이주 UIW-6의 성장 최적 탄소원은 fructose와 sucrose였으며 질소원은 yeast extract> tryptone> peptone 순으로 이용하였다. 변이주 UIW-6는 공시균주로 사용한 IW 보다 성장이 빨라 황 화합물 악취 제거에 효과적으로 이용할 수 있는 유용한 변이주로 판단되어진다.

• 자연과학논문집
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• 제8권1호
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• pp.33-39
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• 1995

Klebsiella sp. L-10을 N-methyl-N'-nitro-N''-nitrosoguanidine 과 ethylmethane sulfornate 및 자외선 등으로 돌연변이시켜 히아루론산 복합체의 수율이 친주보다 약 2.5배 증대된 NTG 50 변이주를 얻었다. NTG 50변이주를 이용한 히아루론산 복합체의 최적 생산배지 조성은 효모 추출물 0.1%, 트립톤 3%, 포도당 3%, $K_2HPO_4$ 와 $KH_2PO_4$ 각각 30nM 이었고 배양조건은 배지의 초기 pH 6.0-6.5, 배양온도 $37^{\circ}C$, 24시간의 진탕배양이었으며 이때 배양액 리터당 2900mg의 히아루론산 복합체가 생산되었다.

• 미생물학회지
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• 제20권3호
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• pp.125-133
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• 1982

Mutational experiments were performed to imporve the cellulase productivity of Aspergillus phoenicis KU175, isolated from the southern part of Korea, as a high cellulase producer. By treatment ultra-violet light nad 4-NQO(4-Nitroquinoline-N-Oxide), mutation waas induced, and treatment ultra-violet light and 4-NQO (4-Nitroquinoline-N-Oxide), mutation was induced, and A.phoenicis KU175-115 was finally selected for its highest avicelase production. Avicelase production of the mutant was increased about 2 times compared with those of the wild strain. However, activities of other hydrolytic enzymes, such as amylase, protease and nuclease, of the mutant strain didn't show a marked difference compared with those of the nuclease, of the mutant strain didn't show a marked difference compared with the wild strain, except slight increase in ribonuclease activity and slight decrease in glucoamylase activity. Avicelases from the mutant strain selected were purified from wheat bran culture by successive salting out, followed by dialysis and column chromatography, and their charcteristics were compared with thosw of the wild strain. Avicelase was separated into three peaks in the mutant strain as well as in the case of wild strain. Avicelase II activity of the mutant strain was prominently higher than that of the wild strain, while avicelase I and III activities of those were equivalent. The optimal pH ranges and stability of avicelase II from the mutant strain were pH4-5 and pH3.5-6.0, respectively, as well as in the case of the wild strain. The optimal temperature and thermal stability of avicelase II from the mutant strain were $40{\sim}50^{\circ}C\;and\;20{\sim}55^{\circ}C$, respectively. These results were same as those of the wild strain. By the using of Eadie-Hofastee plot, $K_m\;and\;V_{max}$ of avicelase II from the mutant and the wild strain were calculated to be 2.29mg/ml and $4.84{\mu}g$ reducing sugar as glucose per min equally, from the line fitted to the data by the least square method. Activity of avicelase II from the mutant strain was slightly activated by $Mg^{++}\;but\;inhibited\;by\;Cu^{++}, \;Mn^{++}\;and\;Zn^{++}$, as well as in the case of the wild strain. Therefore, it was concluded that the mutant didn't induce the formation of another avicelase isozyme, or the changes in the properties of avicelase, but induce the changes in the productively of the same avicelase II by the action of regulatory gane.

• 식품기술
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• 제17권4호
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• pp.98-106
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• 2004

Two mutant enzymes of $\gamma$-glutamylcysteine synthetase ($\gamma$-GCS) which catalyzed the synthesis of $\gamma$-glutamylcysteine from L-glutamic acid and L-cysteine in the presence of ATP, were prepared bypoint mutation of $\gamma$-GCS gene with site-directed mutagensis in E. coli. Conformational structuresand catalytic reaction kinetics of mutant enzymes were compared with wild type $\gamma$-GCS afterpurification. The S495F mutant enzyme (serine at 495 residue was substituted with phenylalanine),which had no catalytic activity for $\gamma$-glutamylcysteine synthesis, rarely folded even in neutral pH.However, the mutant A494V (alanine of 494 residue was replaced by valnine) which showed 50 %increase of activity, had a high folding structure. The folding structure of A494V also more stable athigh temperature and extreme pH compared to wild type and S495F. Reaction kinetics of wild typeand A494V were also investigated, Km value of A494V was smaller than that of wild type, while itshowed a little difference at Vmax values. This result evolved that alanine at 494 may be involved inbinding site of substrate rather than catalytic site. In addition, change of catalytic activity by onepoint mutation was highly correlated with the folding structure of enzyme.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1533-1537
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• 2007

In this study, in order to develop a continuous production process of lactosucrose in a packed-bed reactor, Sterigmatomyces elviae ATCC 18894 was selected and mutated. The mutant strain of S. elviae showed 54.3% higher lactosucrose production than the wild type. Reaction conditions such as temperature, pH, substrate concentration and flow rate were also optimized. Under optimized reaction conditions ($50^{\circ}C$, pH 6.0, 25% sucrose and 25% lactose as substrate, flow rate 1.2 ml/min), the maximum concentration of lactosucrose (192 g/l) was obtained. In a packed-bed reactor, continuous production of lactosucrose was performed using S. elviae mutant immobilized in calcium alginate, and about 180 g/l of lactosucrose production was achieved for 48 days.

• 대한의생명과학회지
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• 제2권1호
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• pp.21-30
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• 1996

Mitogen-activated protein (MAP) kinase는 여러 세포증식 촉진인자들에 의하여 자신이 인산화됨으로써 활성화되어 다른 protein kinase를 인산화시키는 역할을 하는 세포내 신호전달의 중요한 효소이다. 본 연구에서는 P388 murine leukemia 세포 파쇄액에서 SP sephadex C-50, phenyl superose, Mono Q column을 통하여 MAP kinase를 분리한 결과, 44 kD와 66kD의 isoform을 확인할 수 있었다. 면역 T 세포의 $p56^{kk}$의 N-terminal로부터 유전자 재조합 방법을 통하여 glutathion-s-transferase(GST) fusion protein을 얻은 후 분리한 MAP kinase의 기질로 사용하여 본 결과, wild type과 mutant간에 인산화 정도의 차이를 확인할 수 있어 MAP kinase의 또 다른 기질로 이용할 수 있는 가능성을 제시하였다.

• 미생물학회지
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• 제40권2호
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• pp.160-166
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• 2004

The optimal conditions for production of Monascus sp. KM100l cell mass on submerged culture and production of monacolin K on rice solid culture were investigated. An overproducing mutant of Monascus pigments, KM 1001 mutant, from Monascus purpureus KCCM60016 was selected by NTG treatment. The optimal medium for the production of KM100l mutant cell mass is instructed to be composed of 3% glucose, 2% yeast extract, 0.1 % KH$_2$PO$_4$, 0.05% The optimal conditions for production of Monascus sp. KM100l cell mass on submerged culture and production of monacolin K on rice solid culture were investigated. An overproducing mutant of Monascus pigments, KM 1001 mutant, from Monascus purpureus KCCM60016 was selected by NTG treatment. The optimal medium for the production of KM100l mutant cell mass is instructed to be composed of 3% glucose, 2% yeast extract, 0.1 % KH$_2$The optimal conditions for production of Monascus sp. KM100l cell mass on submerged culture and production of monacolin K on rice solid culture were investigated. An overproducing mutant of Monascus pigments, KM 1001 mutant, from Monascus purpureus KCCM60016 was selected by NTG treatment. The optimal medium for the production of KM100l mutant cell mass is instructed to be composed of 3% glucose, 2% yeast extract, 0.1 % $(KH_2PO_4$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.2% L-asparagine, pH 4.5, and the optimal inoculum size and shaking speed were $1.5{\times}10^6$ spores/50 m1 medium and 150 rpm, respectively. On optimal conditions, 4.1 g/l of the cell mass was obtained at 28$^{\circ}C$ for 3 days. The mycelium were inoculated on 500 g of steamed rice using vinyl bag ($30.6{\times}44$ cm) and incubated at $30^{\circ}C$, 85% humidity for 21 days. Lactone form monacolin K was rapidly increased for 2 days and reached highest concentration of monacolin K (2,930 mg/kg) for 15 days, and monacolin K was decreased after 15 days.