• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.111-118
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• 1998

A bacterium producing unique antistaphylococcal substance (ASS) was isolated from soil samples. The isolated strain KUH-001 was identified to belong to Pseudomonas species from the characteristic properties of its fluorescence and cellular 3-hydroxy fatty acid composition, etc. The ASS component was purified by procedures employing activated carbon adsorption, column chromatography with silica gel, preparative TLC and HPLC. This compound could also be purified mainly by repeating of trituration and precipitation with chilled ether. Purified ASS with a m.p. value of $140~142^{\circ}C$ showed marked stability at high temperature (at $121^{\circ}C$ for 10 min) and extreme pHs (in 1N HC1 and 1N NaOH for 1 day) without significant loss of antibiotic activity. From spectral data of UV, IR, NMR, and FAB-MS, the compound was elucidated as 2-heptyl-4-hydroxyquinoline N-oxide (HHQO). Under the conditions employed, HHQO exhibited a narrow antimicrobial spectrum. active particularly against Staphylococcus aureus including the methicillin resistant strain. Moreover, it did not induce resistance, and besides, interacted synergistically with certain antibiotics such as vancomycin or erythromycin.

• 생명과학회지
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• 제18권3호
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• pp.418-421
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• 2008

호기적으로 자란 Bacillus cereus KCTC 3674로 부터 조제된 막은 NADH만을 산화하고, deamino-NADH는 거의 산화하지 않았다. 호홉쇄와 연계된 NADH oxidase계는 $K_m$ 값이 약 65 ${\mu}M$이였다. 한편, NADH oxidase계 중 NADH: menadione oxidoreductase의 효소학적 특성이 조사되었다. NADH: menadione oxidoreductase의 최고활성은 0.1 M KCl (또는 NaCl) 존재 하에서 pH 9.5에서 얻어졌다. NADH: menadione oxidoreductase의 활성은 rotenone, capsaicin, $AgN0_3$와 같은 호흡저해제에 매우 저항적이였다. 그러나 매우 흥미롭게도 NADH: menadione oxidoreductase의 활성은 HQNO (2-heptyl-4-hydroxyquinoline-N-oxide)와 같은 저해제에 의해서는 오히려 촉진되어 졌다.

• 생명과학회지
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• 제16권3호
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• pp.505-509
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• 2006

호기적으로 자란 Bacillus cereus KCTC 3674로 부터 조제된 막은 NADH만을 산화하고, deamino-NADH는 거의 산화하지 않았다. 호흡쇄와 연계된 NADH oxidase계는 $K_m$ 값이 약 $65\;{\mu}M$ 이였다. NADH:DCIP oxidoreductase의 활성은 $Na^+$또는 $K^+$에 의해 감소되었다. 그 최적 pH는 5.5 였다. NADH:DCIP oxidoreductase의 활성은 rotenone, capsaicin, $AgNO_3$와 같은 호흡저해제에는 매우 저항적 이 였지만, $40{\mu}M$ HQNO (2-heptyl-4-hydroxyquinoline-N-oxide) 존재하에서는 약 40% 저해되었다. 이들 결과로 부터, Bacillus cereus KCTC 3674의 호기적 호흡쇄와 연계된 NADH oxidase계는 energy coupling site가 결여된 HQNO-sensitive NADH:DCIP oxidoreductase를 소유하고 있는 것으로 추정된다.

• Journal of Microbiology and Biotechnology
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• 제13권2호
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• pp.225-229
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• 2003

Each oxidoreductase activity of the aerobic respiratory chain-linked NADH oxidase system in the marine bacterium Pseudomonas nautica was stimulated by monovalent cations including $Na^+,\;Li^+,\;and\;K^+$. In the presence of NADH or deamino-NADH as electron donors, $GH_2$ formation was approximately 1.3-fold higher in the presense of 0.08 M of $Na^+\;than\;K^+$, Whereas the other reductase activities were not significantly higher in $Na^+\;than\;K^+$. The optimal pH of NADH (or deamino-NADH):ubiquinone-1 oxidoreductase was 9.0 in the presence of 0.08 M NaCl. The activity of NADH (or deamino-NADH):ubiquinone-1 oxidoreductase was inhibited by about 33% with $60{\mu}M$ 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). The activity of NADH (deamino-NADH): ubiquinone-1 oxidoreductase was inhibited by about 32 to 38% with $80{\mu}M$ rotenone, whereas the activity was highly resistant to capsaicin. On the other hand, electron transfer from NADH or deamino-NADH to ubiquinone-1 generated a membrane potential (${\Delta}{\psi}$) which was larger in the presence of $Na^+$ than that observed in the absence of $Na^+$. The ${\Delta}{\psi}$ was almost completely collapsed by $5{\mu}M$ carbonylcyanide m-chlorophenylhydrazone(CCCP), and approximately 50% inhibited by $100{\mu}M$ rotenone, or $60{\mu}M$ 2-heptyl-4-hydroxyquinoline (HQNO). Also, HQNO made the ${\Delta}{\psi}$ very unstable. The results suggest that the enzymatic and energetic properties of the NADH:ubiquinone oxidoreductase of P. nautica are quite different, compared with those of other marine halophilic bacteria.

• 미생물학회지
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• 제30권6호
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• pp.432-437
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• 1992

When $H^{2}$ was provided as the electron donor, optimum $O_{2}$ levels for growth of Wolinella succinogenes ATCC 29543 were 2% and 8% on brucella agar and in brucella broth, respectively. No growth occurred under 21% $O_{2}$, and scant or no growth occurred under anaerobic condition. $O_{2}$ uptake was inhibited by cyanide and 2-heptyl-4-hydroxyquinoline N-oxide. Protons were translocated out of the cell when oxygen was used as the terminal electron accetor. The $H^{+}$/O ratio with $H_{2}$ and formate as an electron donor were 1, 97 and 1.49, respectively. Proton translocation was inhibited by the protonophore carbonylcyanide m-chlorophenylhydrazone.e.

• 한국균학회지
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• 제19권1호
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• pp.32-40
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• 1991

느타리버섯을 사용하여, 빛이 버섯의 체내 대사에 영향을 미치는지, 영향을 미친다면 어떤 영역의 빛이 작용하는 지를 연구하였다. 이들 결과를 비교 검토하기 위해 재배 지역이 다른 느타리버섯 중의 mitochondria를 설탕 밀도 단계 기울기 원심분리법에 의하여 설탕 농도 44%층에서 분리 정제하여 실험한 결과 다음과 같은 결론을 얻었다. 1. 파장 변화에 따른 mitochondrial ATP synthase의 활성도는 490nm에서 가장 크게 활성화되었다. 2. 최적 파장 490nm에서 빛 조사 시간 변화에 따른 ATP synthase의 활성도는 15초 동안 조사하였을 때 가장 활성화 되었다. 3. 최적 조건에서 ATP synthase는 phenazine methosulfate(PMS)에 의해 224% 활성화 되었으며, 2,6-dichlorophenol indophenol(DCPIP)에 의하여 168% 활성화 되었다. 한편, oligomycin에 의해서는 90% 효소 활성이 억제 되었으며, 2,4-dinitrophenol(DNP)에 의해서 75%, 2-heptyl-4-hydroxyquinoline-N-oxide(HQNO)에 의해 15% 효소활성이 억제되었다. 4. 최적 조건에서 ATP synthase는 $Mn^{2+}$에 의해 73%의 효소 활성 억제를 보였고, $Ca^{2+}$에 의해 35%, $Co^{2+}$에 의해 14%의 효소 활성 억제를 보였다. 5. 최적조건에서 ATP synthase는 $CN^{-}$과 $SO_{4}\;^{2-}$에 의하여 각각 80%, 46% 효소활성이 억제되었고, $NO_{3}\;^{-}$과 $CO_{3}\;^{2-}$에 의해서는 28%의 효소 활성 억제를 보였다. 이상과 같은 결과를 통해 버섯의 종류에 관계없이 청색광 영역의 빛에 의해 활성화 된다는 것과 그 광수용체도 유사한 형태일 것이라 예측할 수 있다.

• BMB Reports
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• 제37권6호
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• pp.753-756
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• 2004

Membranes prepared from Bacillus cereus KCTC 3674, grown aerobically on a complex medium, oxidized NADH exclusively, whereas deamino-NADH was little oxidized. The respiratory chain-linked NADH oxidase exhibited an apparent $K_m$ value of approximately $65\;{\mu}m$ for NADH. The maximum activity of the NADH oxidase was obtained at about pH 8.5 in the presence of 0.1 M KCl (or NaCl). Respiratory chain inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) inhibited the activity of the NADH oxidase by about 90% at a concentration of $40\;{\mu}m$. Interestingly, rotenone and capsaicin inhibited the activity of the NADH oxidase by about 60% at a concentration of $40\;{\mu}m$ and the activity was also highly sensitive to $Ag^+$.

• BMB Reports
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• 제40권1호
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• pp.53-57
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• 2007

The enzymatic properties of NADH:quinone oxidoreductase were examined in Triton X-100 extracts of Bacillus cereus membranes by using the artificial electron acceptors ubiquinone-1 and menadione. Membranes were prepared from B. cereus KCTC 3674 grown aerobically on a complex medium and oxidized with NADH exclusively, whereas deamino-NADH was determined to be poorly oxidized. The NADH oxidase activity was lost completely by solubilization of the membranes with Triton X-100. However, by using the artificial electron acceptors ubiquinone-1 and menadione, NADH oxidation could be observed. The activities of NADH:ubiquinone-1 and NADH:menadione oxidoreductase were enhanced approximately 8-fold and 4-fold, respectively, from the Triton X-100 extracted membranes. The maximum activity of FAD-dependent NADH:ubiquinone-1 oxidoreductase was obtained at about pH 6.0 in the presence of 0.1M NaCl, while the maximum activity of FAD-dependent NADH:menadione oxidoreductase was obtained at about pH 8.0 in the presence of 0.1M NaCl. The activities of the NADH:ubiquinone-1 and NADH:menadione oxidoreductase were very resistant to such respiratory chain inhibitors as rotenone, capsaicin, and $AgNO_3$, whereas these activities were sensitive to 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). Based on these results, we suggest that the aerobic respiratory chain-linked NADH oxidase system of B. cereus KCTC 3674 possesses an HQNO-sensitive NADH:quinone oxidoreductase that lacks an energy coupling site containing FAD as a cofactor.

• 한국균학회지
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• 제17권2호
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• pp.99-104
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• 1989

1. 최적광조사 조건, 470 nm에서 15초 동안 빛을 조사한 미토콘드리아성 ATP synthase는 1mmole DCPI에 의하여 그 활성이 85% 증가되었다. 2. 1mmole DNP, $10\;{\mu}mole$ HHQNO 및 $100\;{\mu}g/ml$의 oligomycin은 이 효소의 활성을 각각 61, 41% 및 12% 억제시켰다. 3. 최적 조건의 빛에 의한 $Fe^{3+}$ 및 $Fe^{2+}$ 이온의 유입효과에서, 5mmole $Fe^{3+}$ 및 0.5mmole $Fe^{2+}$ 이온에 의하여 이 효소 활성이 각각 14% 및 12% 증가되었다. 4. 광증감제인 phenazine methosulfate의 존재하에서 470nm의 빛을 조사한 후의 효소의 활성도가 크게 증가되는 것으로 보아, 미토콘드리아성 ATP synthase내에 미지의 흡광물질이 존재함을 추정할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.391-396
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• 1996

The Gram-negative marine bacterium Marinomonas vaga, which requires 0.5 M NaCl concentration for optimal growth, is slightly halophilic. The growth of M vaga was highly resistant to the proton conductor, carbonyl cyanide m-chlorophenylhydrazone (CCCP) under alkaline pH conditions (pH 8.5) but very sensitive to CCCP under acidic pH conditions (pH 6.5). These results suggest that the respiratory chain-linked NADH oxidase system of M. vaga may lead to generation of a $Na^{+}$ electrochemical gradient. In order to examine the existence of $Na^{+}$-stimulated NADH oxidase in M. vaga, membrane fractions were prepared by the osmotic lysis method. The membrane-bound NADH oxidase oxidized both NADH and deamino-NADH as substrates and required $Na^{+}$ for maximum activity. The maximum activity of NADH oxidase was obtained at about pH 8.5 in the presence of 0.2 M NaCl. The site of $Na^{+}$-dependent activation in the NADH oxidase system was at the NADH:quinone oxidoreductase segment. The NADH oxidase and NADH:quinone oxidoreductase were very sensitive to the respiratory chain inhibitor, 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) in the presence of 0.2 M NaCl but highly resistant to another respiratory inhibitor, rotenone. Based on these findings, we conclude that M. vaga possesses the $Na^{+}$-dependent NADH:quinone oxidoreductase that may function as an electrogenic $Na^{+}$ pump.