Abstract
In an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114, photosynthetic electron transfer (photooxidation of cytochromes) and light-driven proton release did not occur under anaerobic conditions. 'Auxiliary oxidants', such as nitrate, nitrite, trimethylamine N-oxide (TMAO) and chlorate, restored the optimal redox state for the photosynthetic electron transfer system, resulting in the photooxidation of c-type cytochrome and the release of protons from intact cells on illumination. These auxiliary oxidants oxidized c-type cytochrome(s) under anaerobic conditions in the dark, suggesting the presence of reductases for these auxiliary oxidants. The redox level of the electron transfer chain shifted towards oxidation in the presence of the auxiliary oxidants and was poised to allow photosynthetic electron transfer. KCN inhibited the photooxidation of cytochromes and the light-driven proton release in the presence of these auxiliary oxidants, except for TMAO. KCN also inhibited the auxiliary oxidant-induced oxidation of cytochromes. This suggests that KCN inhibits the reductases for these oxidants. Antimycin and myxothiazol enhanced the auxiliary oxidant-induced oxidation of cytochrome(s), suggesting the involvement of the cytochrome b-c1 complex in nitrate, chlorate and nitrite reduction.
| Original language | English |
|---|---|
| Pages (from-to) | 26-33 |
| Number of pages | 8 |
| Journal | BBA - Bioenergetics |
| Volume | 935 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Aug 17 1988 |
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All Science Journal Classification (ASJC) codes
- Biophysics
- Biochemistry
- Cell Biology
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Restoration of the optimal redox state for the photosynthetic electron transfer system by auxiliary oxidants in an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114. / Takamiya, Ken ichiro; Arata, Hiroyuki; Shioi, Yuzo; Doi, Michio.
In: BBA - Bioenergetics, Vol. 935, No. 1, 17.08.1988, p. 26-33.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Restoration of the optimal redox state for the photosynthetic electron transfer system by auxiliary oxidants in an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114
AU - Takamiya, Ken ichiro
AU - Arata, Hiroyuki
AU - Shioi, Yuzo
AU - Doi, Michio
PY - 1988/8/17
Y1 - 1988/8/17
N2 - In an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114, photosynthetic electron transfer (photooxidation of cytochromes) and light-driven proton release did not occur under anaerobic conditions. 'Auxiliary oxidants', such as nitrate, nitrite, trimethylamine N-oxide (TMAO) and chlorate, restored the optimal redox state for the photosynthetic electron transfer system, resulting in the photooxidation of c-type cytochrome and the release of protons from intact cells on illumination. These auxiliary oxidants oxidized c-type cytochrome(s) under anaerobic conditions in the dark, suggesting the presence of reductases for these auxiliary oxidants. The redox level of the electron transfer chain shifted towards oxidation in the presence of the auxiliary oxidants and was poised to allow photosynthetic electron transfer. KCN inhibited the photooxidation of cytochromes and the light-driven proton release in the presence of these auxiliary oxidants, except for TMAO. KCN also inhibited the auxiliary oxidant-induced oxidation of cytochromes. This suggests that KCN inhibits the reductases for these oxidants. Antimycin and myxothiazol enhanced the auxiliary oxidant-induced oxidation of cytochrome(s), suggesting the involvement of the cytochrome b-c1 complex in nitrate, chlorate and nitrite reduction.
AB - In an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114, photosynthetic electron transfer (photooxidation of cytochromes) and light-driven proton release did not occur under anaerobic conditions. 'Auxiliary oxidants', such as nitrate, nitrite, trimethylamine N-oxide (TMAO) and chlorate, restored the optimal redox state for the photosynthetic electron transfer system, resulting in the photooxidation of c-type cytochrome and the release of protons from intact cells on illumination. These auxiliary oxidants oxidized c-type cytochrome(s) under anaerobic conditions in the dark, suggesting the presence of reductases for these auxiliary oxidants. The redox level of the electron transfer chain shifted towards oxidation in the presence of the auxiliary oxidants and was poised to allow photosynthetic electron transfer. KCN inhibited the photooxidation of cytochromes and the light-driven proton release in the presence of these auxiliary oxidants, except for TMAO. KCN also inhibited the auxiliary oxidant-induced oxidation of cytochromes. This suggests that KCN inhibits the reductases for these oxidants. Antimycin and myxothiazol enhanced the auxiliary oxidant-induced oxidation of cytochrome(s), suggesting the involvement of the cytochrome b-c1 complex in nitrate, chlorate and nitrite reduction.
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UR - http://www.scopus.com/inward/citedby.url?scp=0002438297&partnerID=8YFLogxK
U2 - 10.1016/0005-2728(88)90104-1
DO - 10.1016/0005-2728(88)90104-1
M3 - Article
AN - SCOPUS:0002438297
VL - 935
SP - 26
EP - 33
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 1
ER -