Details
| Original language | English |
|---|---|
| Pages (from-to) | 2617-2623 |
| Number of pages | 7 |
| Journal | Journal of Experimental Biology |
| Volume | 211 |
| Issue number | 16 |
| Publication status | Published - Aug 2008 |
| Externally published | Yes |
Abstract
Sulfide oxidation in the lugworm, Arenicola marina (L.), is most likely localized in the mitochondria, which can either produce ATP with sulfide as a substrate or detoxify it via an alternative oxidase. The present study identified selective activators of the energy-conserving and the detoxifying sulfide oxidation pathways respectively. In the presence of the ROS scavengers glutathione (GSH) and ascorbate, isolated lugworm mitochondria rapidly oxidized up to 100 μmol l-1 sulfide with maximal oxygen consumption rates but did not produce any ATP in the process. Under these conditions, salicylhydroxamic acid (SHAM), which is an inhibitor of the alternative oxidase of plant mitochondria, completely blocked oxygen consumption whereas inhibitors of complex III and IV had hardly any effect. By contrast, dehydroascorbate (DHA) enabled the mitochondria to gain ATP from sulfide oxidation even if the sulfide concentration far exceeded the threshold for inhibition of cytochrome oxidase. In the presence of dehydroascorbate, respiratory rates were independent of sulfide concentrations, with a respiratory control ratio of 2.1±0.2, and both oxygen consumption and ATP production were completely inhibited by myxothiazol and sodium azide but only marginally by SHAM. The present data indicate that a redox mechanism may contribute to the regulation of sulfide oxidation in lugworm mitochondria in vivo. Thus, mitochondria are presumably much more sulfide resistant in a cellular context than previously thought.
Keywords
- Alternative oxidase, Arenicola marina, Ascorbate, ATP production, Dehydroascorbate, Glutathione, Redox regulation, Sulfide oxidation
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Ecology, Evolution, Behavior and Systematics
- Biochemistry, Genetics and Molecular Biology(all)
- Physiology
- Agricultural and Biological Sciences(all)
- Aquatic Science
- Agricultural and Biological Sciences(all)
- Animal Science and Zoology
- Biochemistry, Genetics and Molecular Biology(all)
- Molecular Biology
- Agricultural and Biological Sciences(all)
- Insect Science
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In: Journal of Experimental Biology, Vol. 211, No. 16, 08.2008, p. 2617-2623.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Redox regulation of mitochondrial sulfide oxidation in the lugworm, Arenicola marina
AU - Hildebrandt, Tatjana M.
AU - Grieshaber, Manfred K.
PY - 2008/8
Y1 - 2008/8
N2 - Sulfide oxidation in the lugworm, Arenicola marina (L.), is most likely localized in the mitochondria, which can either produce ATP with sulfide as a substrate or detoxify it via an alternative oxidase. The present study identified selective activators of the energy-conserving and the detoxifying sulfide oxidation pathways respectively. In the presence of the ROS scavengers glutathione (GSH) and ascorbate, isolated lugworm mitochondria rapidly oxidized up to 100 μmol l-1 sulfide with maximal oxygen consumption rates but did not produce any ATP in the process. Under these conditions, salicylhydroxamic acid (SHAM), which is an inhibitor of the alternative oxidase of plant mitochondria, completely blocked oxygen consumption whereas inhibitors of complex III and IV had hardly any effect. By contrast, dehydroascorbate (DHA) enabled the mitochondria to gain ATP from sulfide oxidation even if the sulfide concentration far exceeded the threshold for inhibition of cytochrome oxidase. In the presence of dehydroascorbate, respiratory rates were independent of sulfide concentrations, with a respiratory control ratio of 2.1±0.2, and both oxygen consumption and ATP production were completely inhibited by myxothiazol and sodium azide but only marginally by SHAM. The present data indicate that a redox mechanism may contribute to the regulation of sulfide oxidation in lugworm mitochondria in vivo. Thus, mitochondria are presumably much more sulfide resistant in a cellular context than previously thought.
AB - Sulfide oxidation in the lugworm, Arenicola marina (L.), is most likely localized in the mitochondria, which can either produce ATP with sulfide as a substrate or detoxify it via an alternative oxidase. The present study identified selective activators of the energy-conserving and the detoxifying sulfide oxidation pathways respectively. In the presence of the ROS scavengers glutathione (GSH) and ascorbate, isolated lugworm mitochondria rapidly oxidized up to 100 μmol l-1 sulfide with maximal oxygen consumption rates but did not produce any ATP in the process. Under these conditions, salicylhydroxamic acid (SHAM), which is an inhibitor of the alternative oxidase of plant mitochondria, completely blocked oxygen consumption whereas inhibitors of complex III and IV had hardly any effect. By contrast, dehydroascorbate (DHA) enabled the mitochondria to gain ATP from sulfide oxidation even if the sulfide concentration far exceeded the threshold for inhibition of cytochrome oxidase. In the presence of dehydroascorbate, respiratory rates were independent of sulfide concentrations, with a respiratory control ratio of 2.1±0.2, and both oxygen consumption and ATP production were completely inhibited by myxothiazol and sodium azide but only marginally by SHAM. The present data indicate that a redox mechanism may contribute to the regulation of sulfide oxidation in lugworm mitochondria in vivo. Thus, mitochondria are presumably much more sulfide resistant in a cellular context than previously thought.
KW - Alternative oxidase
KW - Arenicola marina
KW - Ascorbate
KW - ATP production
KW - Dehydroascorbate
KW - Glutathione
KW - Redox regulation
KW - Sulfide oxidation
UR - http://www.scopus.com/inward/record.url?scp=52649125410&partnerID=8YFLogxK
U2 - 10.1242/jeb.019729
DO - 10.1242/jeb.019729
M3 - Article
C2 - 18689415
AN - SCOPUS:52649125410
VL - 211
SP - 2617
EP - 2623
JO - Journal of Experimental Biology
JF - Journal of Experimental Biology
SN - 0022-0949
IS - 16
ER -