• Proceedings of the Korean Society of Life Science Conference
• /
• 2003.10a
• /
• pp.130-130
• /
• 2003

• Journal of Microbiology and Biotechnology
• /
• v.7 no.5
• /
• pp.356-359
• /
• 1997

To study the relationship between oxygen tolerance and enzyme activity in the oxygen metabolism of bifidobacteria, the activities of catalase, superoxide dismutase (SOD), NADH oxidase and NADH peroxidase from six typical bifidobacteria and other bacteria were assayed by spectrophotometry. Catalase activity was hardly detected in any of the bifidobacteria tested. SOD activity was detected in every species including the Clostridium species. In particular SOD activity was notably high in the aerosensitive Bifidobacterium adolescentis. This fact indicates that SOD activity is not a critical factor to ensure aerotolerance. Aerosensitive B. adolescentis showed very low NADH oxidative enzyme activity whereas other aerotolerant bifidobacteria exhibited considerable activity for the enzymes. It seems that detoxification of $H_2O_2$ by NADH oxidative enzymes might be an important factor in improving for aerotolerant bifidobacteria survival rates in an oxygen environment.

• The Korean Journal of Pharmacology
• /
• v.23 no.2
• /
• pp.113-121
• /
• 1987

Local anesthetics were investigated for their effects on mitochondrial electron transport system, production of superoxide radical from submitochondrial particles and malondialdehyde production through lipid per oxidation. Local anesthetics had various effects on activities of enzymes in electron transport chain. The activities of NADH dehydrogenase, NADH oxidase and NADH-ubiquinone oxidoreductase were effectively inhibited by lidocaine, procaine and dibucaine but slightly influenced by cocaine. The activities of succinate dehydrogenase, succinate-cytochrome c oxidoreductase and succinate-ubiquinone oxidoreductase were inhibited by lidocaine and dibucaine, but the succinate oxidase activity was stimulated by local anesthetics. Both dihydroubiquinone-cytochrome c oxidoreductase and cytochrome c oxidase activities were inhibited by local anesthetics. In these reactions, the response of Complex I segment to local anesthetics was greater than other Complex segments. Local anesthetics inhibited both the superoxide production from submitochondrial particles supplemented with succinate or NADH and the enhanced production of superoxide radicals by antimycin. The malondialdehyde production by oxygen free radicals was inhibited by local anesthetics. These results suggest that the inhibition of superoxide and malondialdehyde production caused by local anesthetics may be brought by suppression of the electron transport in mitochondria at sites in or near complex I segment.

• Korean Journal of Veterinary Research
• /
• v.44 no.4
• /
• pp.533-537
• /
• 2004

In this study, we performed a PCR-RFLP analysis of NADH oxidase gene(nox) for the characterization of porcine intestinal spirochetes isolated from Korea by the comparison with Brachyspira hyodysenteriae and B. pilosicoli reference strains. Eleven strains including four reference strains, B. hyodysenteriae B204, B234, B169, B. pilosicoli P43/6/78 and seven Korean isolates were used. PCR products of 939 bp were amplified using nox-specific primers and digested with two restriction enzymes, Bfm I and Dpn II. In study using Bfm I, both strains showed no difference in fragmented size(197 and 741 bp). When use Dpn II, B. hyodysenteriae showed two bands(209 and 684 bp), however B. pilosicoli showed a single band of 896 bp. Our results indicate that nox-specific PCR-RFLP could be used as a typing method of Brachyspira species and as an epidemiological method for identifying spirochetes isolated from swine.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.2
• /
• pp.225-229
• /
• 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.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2003.05a
• /
• pp.131-131
• /
• 2003

• Microbiology and Biotechnology Letters
• /
• v.19 no.2
• /
• pp.153-157
• /
• 1991

Intracellular enzymes of an extreme halophilic bacterium, Halobacterium sp. HE10, isolated from a saltern in Korea was investigated. The membrane-bound enzyme, NADH dehydrogenase, involved in electron transport system was stimulated by the addition of 2.0 M NaCl. The respiratory enzyme activities such as NADH oxidase and NADH dehydrogenase was decreased on removal of $Na^+$ ion and restored when replaced with cations like $K^+$, $Li^+$and $NH_{4}^{+}$ ions. Furthermore, their activities were affected by the anions such like carbonate, acetate, sulfate, chloride and nitrate at the presence of $Na^+$ion. Lactate dehydrogenase activity was highest at the asturated solution of NaCl and isocitrate dehydrogenase activity was a maximum level at 1.0 M NaCl. These results suggested that the enzyme activites of the respiratory chain in Halobacterium sp. EH10 was stimulated by the presence of $Na^+$ ion.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2005.04a
• /
• pp.77-77
• /
• 2005

• Proceedings of the Korean Society of Life Science Conference
• /
• 2005.04a
• /
• pp.78-78
• /
• 2005

• Proceedings of the Korean Society of Life Science Conference
• /
• 2003.05a
• /
• pp.129-129
• /
• 2003