• 미생물학회지
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• 제48권3호
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• pp.180-186
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• 2012

그람 음성균인 녹농균(Pseudomonas aeruginosa)은 다양한 환경에 존재하는 기회감염성 병원균으로, 병원성의 발현에 쿼럼센싱(QS) 기전이 중요한 역할을 담당한다. 녹농균의 여러 QS 신호물질 수용체들 중 하나인 QscR은 다른 QS 수용체들과는 구분되는 특별한 특성들을 가진다. 본 연구에서는 이러한 특성들 중 특히 넓은 신호물질 특이성을 QscR에 부여해 주는 아미노산 잔기가 무엇인지 알아보기 위해, QscR의 72번째 threonine, 132번째 arginine, 140번째 threonine 잔기가 각각 isoleucine, methionine, isoleucine 잔기로 치환된 돌연변이 QscR들($QscR_{T72I}$, $QscR_{R132M}$, $QscR_{T140I}$)을 제조하였다. 이들의 활성을 측정해 보았을 때 $QscR_{R132M}$은 N-3-oxododecanoyl homoserine lactone (3OC12-HSL)에 대한 반응성이 사라졌고, $QscR_{T72I}$와 $QscR_{T140I}$는 민감성이 많이 감소하기는 하였으나 여전히 3OC12-HSL에 대한 반응성을 가지고 있었다. 이들 돌연변이 QscR들에 다양한 구조의 acyl-HSL을 처리해 보았을 때, $QscR_{T72I}$와 $QscR_{T140I}$는 야생형 QscR처럼 자기 자신의 신호물질인 3OC12-HSL 보다 N-decanoyl HSL (C10-HSL)이나 N-dodecanoyl HSL (C12-HSL)처럼 10개 혹은 12개의 탄소 사슬을 가지면서 3번째 탄소에 oxo-moiety가 없는 acyl-HSL에 대해 더 높은 반응성을 보였으며, $QscR_{R132M}$은 3OC12-HSL 뿐만 아니라 본 연구에서 사용된 어떤 acyl-HSL에도 반응성을 보이지 않았다. 또한 $QscR_{T72I}$와 $QscR_{T140I}$는 QscR 억제제인 5f에 의해 야생형 QscR과 비슷한 수준으로 활성이 억제되었다. 이러한 결과들은 130번째 arginine의 경우 QscR의 활성과 acyl-HSL들과의 결합에 중요한 역할을 하는 반면, 72번째와 140번째 threonine들의 경우 QscR의 활성에는 중요하지만, 다른 구조의 acyl-HSL들에 대한 선택적 결합이나, 경쟁적 억제자들의 결합 간섭에는 영향을 주지 않음을 시사하는 것이다.

• BMB Reports
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• 제53권4호
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• pp.218-222
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• 2020

Excessive and hyperactive osteoclast activity causes bone diseases such as osteoporosis and periodontitis. Thus, the regulation of osteoclast differentiation has clinical implications. We recently reported that dehydrocostus lactone (DL) inhibits osteoclast differentiation by regulating a nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), but the underlying mechanism remains to be elucidated. Here we demonstrated that DL inhibits NFATc1 by regulating nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and nuclear factor-erythroid 2-related factor 2 (Nrf2). DL attenuated IκBα phosphorylation and p65 nuclear translocation as well as decreased the expression of NF-κB target genes and c-Fos. It also inhibited c-Jun N-terminal kinase (JNK) but not p38 or extracellular signal-regulated kinase. The reporter assay revealed that DL inhibits NF-κB and AP-1 activation. In addition, DL reduced reactive oxygen species either by scavenging them or by activating Nrf2. The DL inhibition of NFATc1 expression and osteoclast differentiation was less effective in Nrf2-deficient cells. Collectively, these results suggest that DL regulates NFATc1 by inhibiting NF-κB and AP-1 via down-regulation of IκB kinase and JNK as well as by activating Nrf2, and thereby attenuates osteoclast differentiation.

• 한국식품과학회지
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• 제27권3호
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• pp.324-328
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• 1995

두부의 제조공정(응고제 종류 및 양, 두유가열온도, 성형압력)에 따른 두부의 물성학적 성질의 변화를 파손강도와 응력완화현상을 이용하여 측정, 분석하였다. 각 응고제$(CaCl_2,\;MgCl_2,\;CaSO_4,\;GDL)$ 중에서 $CaCl_2$가 가장 뛰어난 파손강도를 보였으며 대부분 0.3%에서 최대치를 보였다. 가열온도는 $95^{\circ}C$에서 최대의 강도를 나타내었고 성형압력 15 kgf에서 모든 응고제를 이용한 두부는 성형되었으며, 일반적으로 성형압력이 높을수록 두부조직의 강도도 증가하였다. 각 제조조건에 따른 응력완화 실험에서는 초기응력 값이 파손강도의 결과와 일치하는 경향을 보였고 탄성성분과 점성성분 또한 파손강도의 변화와 같은 경향을 나타내었다. 응력완화실험을 통하여 측정한 두부조직의 물성을 수학적 모델에 적용하여 조직의 변화를 수치화하여 설명하였다.

• Natural Product Sciences
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• 제23권4호
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• pp.291-298
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• 2017

Six dammarane-type triterpenoids, dammar-24-en-$3{\beta}$-ol (1), $3{\beta}$-epicabraleahydroxy lactone (2), (E)-25-hydroperoxydammar-23-en-$3{\beta}$,20-diol (3), dammar-24-en-$3{\beta}$,20-diol (4), $3{\beta}$-acetyl-20S,24S-epoxy-25-hydroxydammarane (5), and $3{\beta}$-epiocotillol (6) were isolated from the methanolic extract of the bark of Aglaia elliptica. The chemical structure were identified on the basis of spectroscopic evidence and by comparison with those spectra previously reported. Compounds 1 - 6 were isolated first time from this plant. Compounds 1 - 6, along with a known synthetic analog, cabraleone (7) were evaluated their cytotoxic activity against P-388 murine leukimia cells in vitro. Among those compounds $3{\beta}$-acetyl-20S,24S-epoxy-25-hydroxydammarane (5) showed strongest cytotoxic activity with $IC_{50}$ value of $8.02{\pm}0.06{\mu}M$.

• 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.

• 생명과학회지
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• 제15권1호
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• pp.147-151
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• 2005

양귀비의 성분중 하나인 $(-)-\alpha-narcotine$은 ethyl chloroformate와 가온반응시 diastereomeric chloro-carbamate 혼한물과 Z/E-enol lactone혼합물을 생성하였는데 이 중에서 Z/E-isomer의 생성비를 HPLC로 측정한 결과 Z:E=1:1.12로 나타나 열역학적으로 불안정한 E-isomer가 다소 많이 생성되었다. 그러나 이 isomer 혼합물을 chromatography로 각각 분리 한 결과, 그 생성 비는 Z:E=7:1로 나타나 분리도중에 column 내 에서 E-isomer가 보다 안정한 Z-isomer로 대부분 변하였음을 알 수 있었다. Z/E-isomer의 생성비가 유사한 구조의 화합물에서 어떻게 변하는지를 관찰하기 위하여 $\beta-narcotine$, deuterated $\beta-narcotine$ 및 $\beta-hydrastine$을 대상으로 동일한 조건하에 반응시킨 결과, 이들의 isomer 생성비율이 구조에 따라 크게 차이가 있음을 알 수 있었으며 그 이유를 설명하였다. 한편, 일반적인 보고와는 달리, narcotine에서 생성된 안정한 Z-isomer는 광화학반응에 의해 불안정한 E-isomer로 쉽게 변한다는 사실도 확인하였다.

• 공업화학
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• 제5권5호
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• pp.801-807
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• 1994

락토오스 치환 스티렌 단량체, N-(p-vinylbenzyl)-D-lactonamide(VLA)는 락토오스락톤과 p-비닐벤질아민과의 아미드화반응을 따라 제조하였고, 비오틴 치환 스티렌 당량체, N-(p-vinylbenzyl)-biotinamide(VBA)는 비오틴의 카르복실기를 N, N'-dicyclohexylcarbodiimide 존재하에서 N-hydroxysuccinimide와 반응하여 활성화된 비오틴을 제조한 것을 이어서 p-비닐벤질아민과 아미드화시켜 합성하였다 합성한 이들 단량체(VLA와 VBA)의 반응 몰비를 바꿔가면서 라디칼 중합에 의하여 공중합체인 poly(vlnytbenzyl-lactonamide-co-vinylbenzylbiotinamide), p(VLA-co-VBA)을 합성하였고, 67~71%의 수율을 얻었다. 합성된 공중합체들은 친수성의 락토오스 부위와 소수성의 비닐벤질 부위 그리고 소량의 biotin 부위를 함께 갖고 있는 양친매성 중합체였음을 기기분석으로 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.631-638
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• 1998

Studies were made to elucidate the cell growth and the production of camptothecin and its derivatives in cell cultures of Camptotheca acuminata. High resolution HPLC chromatograms to analyze camptothecin and 10-hydroxycamptothecin in lactone and carboxylate forms were obtained with a fluorescence detector. Calli inductions were optimized with the young stem of explant on Schenk and Hildebrandt (SH) medium supplemented with 5 mg/l $\alpha$-naphthaleneacetic acid (NAA), 0.2 mg/l 6-benzylamino purine (BAP), 2.0% sucrose, and 0.5% agar. The hybrid medium, a mixture of SH and Murashige and Skoog (MS) salts, was developed for homogeneous suspension cultures without large cell aggregates. The optimum phytohormone concentrations for successful suspension cultures were 1.0mg/l of 2,4-D and 0.5 mg/l of kinetin. The highest growth in suspension cultures was observed when 49.7% (w/w) of the cells was composed of small aggregates which were below 0.1 mm in diameter. Time course changes of cell growth and camptothecin production showed that camptothecin accumulation was started at the end of the growth phase and the maximum content was obtained 10 days after inoculation. Yeast extract elicitor increased camptothecin accumulation 4 times. Methyl jasmonate and jasmonic acid also increased camptothecin production 6 and 11 times, respectively.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1142-1149
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• 2009

Several bioactive metabolites, including pyrrolnitrin, N-acylhomoserine lactones, and polyhydroxyalkanoates were isolated from Burkholderia sp. O33. Effects of various nutrients, including sugars, gluconolactone, glycerol, tryptophan, chloride, and zinc were investigated in relation to the production of these metabolites. Logarithmic increase of pyrrolnitrin was observed between 2-5 days and reached a maximum at 7-10 days. Tryptophan concentration reached the maximum at 3 days, whereas 7-chlorotryptophan was gradually increased throughout the studies. Among various carbon sources, gluconolactone, trehalose, and glycerol enhanced pyrrolnitrin production, whereas strong inhibitory effects were found with glucose. Relative concentrations of pyrrolnitrin and its precursors were in the order of pyrrolnitrin$\gg$dechloroaminopyrrolnitrin or aminopyrrolnitrin throughout the experiments. Among three N-acylhomoserine lactones, the N-octanoyl analog was the most abundant quorum sensing signal, of which the concentrations reached the maximum in 2-3 days, followed by a rapid dissipation to trace level. No significant changes in pyrrolnitrin biosynthesis were observed by external addition of N-acylhomoserine lactones. Polyhydroxyalkanoates accumulated up to 3-4 days and decreased slowly thereafter. According to the kinetic analyses, no strong correlations were found between the levels of pyrrolnitrin, N-acylhomoserine lactones, and polyhydroxyalkanoates.

• Journal of Microbiology and Biotechnology
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• 제7권3호
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• pp.180-188
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• 1997

Bacillus subtilis C9 was selected by measuring the oil film-collapsing activity and produced biosurfactant in a medium containing glucose as a sole carbon source. The biosurfactant emulsified hydrocarbons, vegetable oils and crude oil, and lowered the surface tension of culture broth to 28 dyne/cm. A biosurfactant, C9-BS produced by B. subtilis C9 was purified by ultrafiltration, extraction with chloroform and methanol, adsorption chromatography, and preparative reversed phase HPLC. Structural analyses, IR spectroscopy, FAB mass spectroscopy, amino acid composition, and NMR analyses, demonstrated that C9-BS was a lipopeptide comprising a fatty acid tail and peptide moiety. The lipophilic part consisting of $C_{14}\;or\;C_{15}$ hydroxy fatty acid was linked to the hydrophilic peptide part, which contained seven amino acids (Glu-Leu-Leu-Val-Asp-Leu-Leu) with a lactone linkage.