Abstract
The effect of light on bacteriochlorophyll (Bchl) accumulation as well as the activity of two enzymes in the initial step of the tetrapyrrole biosynthetic pathway was examined in an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114. Light clearly regulated the Bchl and carotenoid accumulation, completely suppressing their levels at high light intensity. However, porphyrin and Bchl precursors were not found in either the cells or the growth medium of lighted culture. The level of Bchl showed an inverse relationship to the light energy flux. Kinetic studies showed a Hill coefficient of n = 3.3 (r = 0.973), indicating a positive cooperativity. Bchl accumulation was stopped immediately upon illumination without any lag or overshoot. Despite low Bchl content, the activities of 5-aminolevulinic acid synthetase and porphobilinogen synthase were rather stimulated, but not suppressed by light. The high activity of enzymes coincided with the results that heme contents, particularly cytochrome c and catalase activity, were increased in light-grown cells. These results suggest that light regulated Bchl accumulation, but not Bchl biosynthesis and that the effect of light is to render newly formed pigment molecules unstable.
| Original language | English |
|---|---|
| Pages (from-to) | 470-477 |
| Number of pages | 8 |
| Journal | Archives of Biochemistry and Biophysics |
| Volume | 266 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Nov 1 1988 |
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All Science Journal Classification (ASJC) codes
- Biophysics
- Biochemistry
- Molecular Biology
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Control of bacteriochlorophyll accumulation by light in an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114. / Shioi, Yuzo; Doi, Michio.
In: Archives of Biochemistry and Biophysics, Vol. 266, No. 2, 01.11.1988, p. 470-477.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Control of bacteriochlorophyll accumulation by light in an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114
AU - Shioi, Yuzo
AU - Doi, Michio
PY - 1988/11/1
Y1 - 1988/11/1
N2 - The effect of light on bacteriochlorophyll (Bchl) accumulation as well as the activity of two enzymes in the initial step of the tetrapyrrole biosynthetic pathway was examined in an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114. Light clearly regulated the Bchl and carotenoid accumulation, completely suppressing their levels at high light intensity. However, porphyrin and Bchl precursors were not found in either the cells or the growth medium of lighted culture. The level of Bchl showed an inverse relationship to the light energy flux. Kinetic studies showed a Hill coefficient of n = 3.3 (r = 0.973), indicating a positive cooperativity. Bchl accumulation was stopped immediately upon illumination without any lag or overshoot. Despite low Bchl content, the activities of 5-aminolevulinic acid synthetase and porphobilinogen synthase were rather stimulated, but not suppressed by light. The high activity of enzymes coincided with the results that heme contents, particularly cytochrome c and catalase activity, were increased in light-grown cells. These results suggest that light regulated Bchl accumulation, but not Bchl biosynthesis and that the effect of light is to render newly formed pigment molecules unstable.
AB - The effect of light on bacteriochlorophyll (Bchl) accumulation as well as the activity of two enzymes in the initial step of the tetrapyrrole biosynthetic pathway was examined in an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114. Light clearly regulated the Bchl and carotenoid accumulation, completely suppressing their levels at high light intensity. However, porphyrin and Bchl precursors were not found in either the cells or the growth medium of lighted culture. The level of Bchl showed an inverse relationship to the light energy flux. Kinetic studies showed a Hill coefficient of n = 3.3 (r = 0.973), indicating a positive cooperativity. Bchl accumulation was stopped immediately upon illumination without any lag or overshoot. Despite low Bchl content, the activities of 5-aminolevulinic acid synthetase and porphobilinogen synthase were rather stimulated, but not suppressed by light. The high activity of enzymes coincided with the results that heme contents, particularly cytochrome c and catalase activity, were increased in light-grown cells. These results suggest that light regulated Bchl accumulation, but not Bchl biosynthesis and that the effect of light is to render newly formed pigment molecules unstable.
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U2 - 10.1016/0003-9861(88)90279-2
DO - 10.1016/0003-9861(88)90279-2
M3 - Article
VL - 266
SP - 470
EP - 477
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -