An EPR study of the pH dependence of formate effects on Photosystem II
Effects of formate on rates of O(2) evolution and electron paramagnetic resonance (EPR) signals were observed in the oxygen evolving PS II membranes as a function of pH. In formate treated PS II membranes, decrease in pH value resulted in the inhibition of the O(2) evolving activity, a decrease in t...
| Veröffentlicht in: | Plant physiology and biochemistry : PPB. - 1991. - 44(2006), 4 vom: 01. Apr., Seite 186-92 |
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| Weitere Verfasser: | , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2006
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| Zugriff auf das übergeordnete Werk: | Plant physiology and biochemistry : PPB |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Formates Photosystem II Protein Complex formic acid 0YIW783RG1 Iron E1UOL152H7 Oxygen S88TT14065 |
| Zusammenfassung: | Effects of formate on rates of O(2) evolution and electron paramagnetic resonance (EPR) signals were observed in the oxygen evolving PS II membranes as a function of pH. In formate treated PS II membranes, decrease in pH value resulted in the inhibition of the O(2) evolving activity, a decrease in the intensity of S(2) state multiline signal but an increase in the intensity of the Q(A)(-)Fe(2+) EPR signal. Time-resolved EPR study of the Y(Z)(*) decay kinetics showed that the light-induced intensity of Y(Z)(*) EPR signal was proportional to the formate concentration. The change in the pH affected both the light-induced intensities and the decay rates of Y(Z)(*), which was found to be faster at lower pH. At 253 K, t(1/e) value of Y(Z)(*) decay kinetics was found to be 8-10 s at pH 6.0 and 18-21 s at pH 5.0. The results presented here indicate that the extent of inhibition at the donor and the acceptor side of PS II due to formate is pH dependent, being more effective at lower pH |
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| Beschreibung: | Date Completed 07.02.2007 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1873-2690 |