Abstract
The abundance of bound Ca2+ in four Photosystem II oxygen-evolving preparations from spinach and rice were determined after removal of contaminating Ca2+ with chelex 100 (Kashino, Y., Satoh, K. and Katoh, S. (1986) FEBS Lett. 205, 150-154). (1) Spinach membrane preparations which evolved oxygen at rates of 350-500 μmol per mg chlorophyll (Chl) per h contained, on average, 1.8 Ca2+ per 200 Chl, whereas a mean value of 2.1 Ca2+ per 200 Chl was obtained with more active spinach preparations, showing oxygen-evolving rates of 500-800 μmol per mg Chl per h. The most active membrane preparations, which evolved oxygen at rates of 750-1050 μmol per mg Chl per h, were isolated from rice seedlings. The rice preparations also contained 2.1 Ca2+ per 200 Chl. Thus, different activities of the three preparations cannot be related to difference in their Ca2+ abundance and the maximum number of Ca2+ needed to promote high rates of oxygen evolution is 2 Ca2+ per 200 Chl in higher plants. (2) Highly purified spinach oxygen-evolving complexes (Ikeuchi, M., Yuasa, M. and Inoue, Y. (1985) FEBS Lett. 185, 316-323) contained 1 Ca2+ per 50 Chl. (3) Treatment of the spinach membrane preparations with high concentrations of NaCl, either in the dark or light, caused no significant loss of the bound Ca2+, although the treatment strongly inhibited oxygen evolution and the inhibition was considerably reversed by addition of 5 mM CaCl2. Exposure of the NaCl-washed membranes to EGTA failed to reduce the amount of bound Ca2+. Thus, inactivation of oxygen evolution by the salt wash is not related to release of Ca2+. (4) The abundance of Ca2+ in spinach membrane preparations was not, or only slightly, affected by treatments with 1 mM NH2OH, 1 M MgCl2 or 0.8 M Tris, which solubilized either Mn or the three extrinsic proteins associated with the membranes, or both. It is concluded that the three proteins are not involved in the Ca2+ binding. The number of Ca2+ functioning in Photosystem II electron transport of higher plants is discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 358-364 |
| Number of pages | 7 |
| Journal | Biochimica et Biophysica Acta - Bioenergetics |
| Volume | 933 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Apr 22 1988 |
| Externally published | Yes |
Fingerprint
Keywords
- Calcium
- NaCl treatment, 23 kDa-
- Oxygen evolution
- Photosystem II
- Protein
ASJC Scopus subject areas
- Biophysics
Cite this
Calcium content of oxygen-evolving Photosystem II preparations from higher plants. Effects of NaCl treatment. / Shen, Jian-Ren; Satoh, Kazuhiko; Katoh, Sakae.
In: Biochimica et Biophysica Acta - Bioenergetics, Vol. 933, No. 2, 22.04.1988, p. 358-364.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Calcium content of oxygen-evolving Photosystem II preparations from higher plants. Effects of NaCl treatment
AU - Shen, Jian-Ren
AU - Satoh, Kazuhiko
AU - Katoh, Sakae
PY - 1988/4/22
Y1 - 1988/4/22
N2 - The abundance of bound Ca2+ in four Photosystem II oxygen-evolving preparations from spinach and rice were determined after removal of contaminating Ca2+ with chelex 100 (Kashino, Y., Satoh, K. and Katoh, S. (1986) FEBS Lett. 205, 150-154). (1) Spinach membrane preparations which evolved oxygen at rates of 350-500 μmol per mg chlorophyll (Chl) per h contained, on average, 1.8 Ca2+ per 200 Chl, whereas a mean value of 2.1 Ca2+ per 200 Chl was obtained with more active spinach preparations, showing oxygen-evolving rates of 500-800 μmol per mg Chl per h. The most active membrane preparations, which evolved oxygen at rates of 750-1050 μmol per mg Chl per h, were isolated from rice seedlings. The rice preparations also contained 2.1 Ca2+ per 200 Chl. Thus, different activities of the three preparations cannot be related to difference in their Ca2+ abundance and the maximum number of Ca2+ needed to promote high rates of oxygen evolution is 2 Ca2+ per 200 Chl in higher plants. (2) Highly purified spinach oxygen-evolving complexes (Ikeuchi, M., Yuasa, M. and Inoue, Y. (1985) FEBS Lett. 185, 316-323) contained 1 Ca2+ per 50 Chl. (3) Treatment of the spinach membrane preparations with high concentrations of NaCl, either in the dark or light, caused no significant loss of the bound Ca2+, although the treatment strongly inhibited oxygen evolution and the inhibition was considerably reversed by addition of 5 mM CaCl2. Exposure of the NaCl-washed membranes to EGTA failed to reduce the amount of bound Ca2+. Thus, inactivation of oxygen evolution by the salt wash is not related to release of Ca2+. (4) The abundance of Ca2+ in spinach membrane preparations was not, or only slightly, affected by treatments with 1 mM NH2OH, 1 M MgCl2 or 0.8 M Tris, which solubilized either Mn or the three extrinsic proteins associated with the membranes, or both. It is concluded that the three proteins are not involved in the Ca2+ binding. The number of Ca2+ functioning in Photosystem II electron transport of higher plants is discussed.
AB - The abundance of bound Ca2+ in four Photosystem II oxygen-evolving preparations from spinach and rice were determined after removal of contaminating Ca2+ with chelex 100 (Kashino, Y., Satoh, K. and Katoh, S. (1986) FEBS Lett. 205, 150-154). (1) Spinach membrane preparations which evolved oxygen at rates of 350-500 μmol per mg chlorophyll (Chl) per h contained, on average, 1.8 Ca2+ per 200 Chl, whereas a mean value of 2.1 Ca2+ per 200 Chl was obtained with more active spinach preparations, showing oxygen-evolving rates of 500-800 μmol per mg Chl per h. The most active membrane preparations, which evolved oxygen at rates of 750-1050 μmol per mg Chl per h, were isolated from rice seedlings. The rice preparations also contained 2.1 Ca2+ per 200 Chl. Thus, different activities of the three preparations cannot be related to difference in their Ca2+ abundance and the maximum number of Ca2+ needed to promote high rates of oxygen evolution is 2 Ca2+ per 200 Chl in higher plants. (2) Highly purified spinach oxygen-evolving complexes (Ikeuchi, M., Yuasa, M. and Inoue, Y. (1985) FEBS Lett. 185, 316-323) contained 1 Ca2+ per 50 Chl. (3) Treatment of the spinach membrane preparations with high concentrations of NaCl, either in the dark or light, caused no significant loss of the bound Ca2+, although the treatment strongly inhibited oxygen evolution and the inhibition was considerably reversed by addition of 5 mM CaCl2. Exposure of the NaCl-washed membranes to EGTA failed to reduce the amount of bound Ca2+. Thus, inactivation of oxygen evolution by the salt wash is not related to release of Ca2+. (4) The abundance of Ca2+ in spinach membrane preparations was not, or only slightly, affected by treatments with 1 mM NH2OH, 1 M MgCl2 or 0.8 M Tris, which solubilized either Mn or the three extrinsic proteins associated with the membranes, or both. It is concluded that the three proteins are not involved in the Ca2+ binding. The number of Ca2+ functioning in Photosystem II electron transport of higher plants is discussed.
KW - Calcium
KW - NaCl treatment, 23 kDa-
KW - Oxygen evolution
KW - Photosystem II
KW - Protein
UR - http://www.scopus.com/inward/record.url?scp=0001167854&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0001167854&partnerID=8YFLogxK
U2 - 10.1016/0005-2728(88)90043-6
DO - 10.1016/0005-2728(88)90043-6
M3 - Article
AN - SCOPUS:0001167854
VL - 933
SP - 358
EP - 364
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 2
ER -