Skip to main content
PMC home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1981 Dec;78(12):7507–7511. doi: 10.1073/pnas.78.12.7507

Stoichiometry, inhibitor sensitivity, and organization of manganese associated with photosynthetic oxygen evolution

C F Yocum *,†, C T Yerkes *, R E Blankenship ‡, R R Sharp §, G T Babcock *,†
PMCID: PMC349297  PMID: 16593134

Abstract

Chloroplast thylakoid membranes isolated in the presence of EDTA retain high rates of O2 evolution (≥340 μmol·h-1·mg chlorophyll-1) but contain no Mn2+ that is detectable by electron paramagnetic resonance (EPR) at room temperature. The total Mn2+ content of these preparations is 4.6 per 400 chlorophylls; 0.6 Mn2+ can be released by addition of Ca2+, a treatment that does not affect O2 evolution. The remaining Mn2+ (4 per 400 chlorophylls) appears to be functionally associated with O2 evolution activity. Inhibition by Tris, NH2OH, or heat will release a small fraction of Mn2+ from these membranes (≈25% with Tris, for example). Addition of Ca2+ further enhances Mn2+ release so that for Tris and for NH2OH, 2 and 3, respectively, Mn2+ per 400 chlorophylls are extracted from the O2-evolving complex. Based on the microwave power-saturation properties of the EPR signal IIf, which arises from an intermediate electron carrier in the water splitting process, it appears that one of the four Mn2+ associated with photosystem II is uniquely sensitive to Tris. A new model is proposed for the organization and inhibitor sensitivity of manganese in the O2-evolving complex.

Keywords: photosynthesis, electron paramagnetic resonance

Full text

PDF
7509

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Babcock G. T., Sauer K. The rapid component of electron paramagnetic resonance signal II: a candidate for the physiological donor to photosystem II in spinach chloroplasts. Biochim Biophys Acta. 1975 Feb 17;376(2):329–344. doi: 10.1016/0005-2728(75)90025-0. [DOI] [PubMed] [Google Scholar]
  2. Blankenship R. E., McGuire A., Sauer K. Rise time of EPR signal IIvf in chloroplast photosystem II. Biochim Biophys Acta. 1977 Mar 11;459(3):617–619. doi: 10.1016/0005-2728(77)90062-7. [DOI] [PubMed] [Google Scholar]
  3. Blankenship R. E., Sauer K. Manganese in photosynthetic oxygen evolution. I. Electron paramagnetic resonance study of the environment of manganese in Tris-washed chloroplasts. Biochim Biophys Acta. 1974 Aug 23;357(2):252–266. doi: 10.1016/0005-2728(74)90065-6. [DOI] [PubMed] [Google Scholar]
  4. Bouges-Bocquet B. Kinetic models for the electron donors of photosystem II of photosynthesis. Biochim Biophys Acta. 1980 Dec;594(2-3):85–103. doi: 10.1016/0304-4173(80)90006-3. [DOI] [PubMed] [Google Scholar]
  5. Dismukes G. C., Siderer Y. Intermediates of a polynuclear manganese center involved in photosynthetic oxidation of water. Proc Natl Acad Sci U S A. 1981 Jan;78(1):274–278. doi: 10.1073/pnas.78.1.274. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Frasch W. D., Cheniae G. M. Flash Inactivation of Oxygen Evolution: IDENTIFICATION OF S(2) AS THE TARGET OF INACTIVATION BY TRIS. Plant Physiol. 1980 Apr;65(4):735–745. doi: 10.1104/pp.65.4.735. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Kohl D. H., Wood P. M. On the Molecular Identity of ESR Signal II Observed in Photosynthetic Systems: The Effect of Heptane Extraction and Reconstitution With Plastoquinone and Deuterated Plastoquinone. Plant Physiol. 1969 Oct;44(10):1439–1445. doi: 10.1104/pp.44.10.1439. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Melis A., Brown J. S. Stoichiometry of system I and system II reaction centers and of plastoquinone in different photosynthetic membranes. Proc Natl Acad Sci U S A. 1980 Aug;77(8):4712–4716. doi: 10.1073/pnas.77.8.4712. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Reinman S., Mathis P., Conjeaud H., Stewart A. Kinetics of reduction of the primary donor of photosystem II. Influence of pH in various preparations. Biochim Biophys Acta. 1981 Apr 13;635(2):429–433. doi: 10.1016/0005-2728(81)90040-2. [DOI] [PubMed] [Google Scholar]
  10. Robinson H. H., Sharp R. R., Yocum C. F. Effect of manganese on the nuclear magnetic relaxivity of water protons in chloroplast suspensions. Biochem Biophys Res Commun. 1980 Apr 14;93(3):755–761. doi: 10.1016/0006-291x(80)91141-9. [DOI] [PubMed] [Google Scholar]
  11. Robinson H. H., Sharp R. R., Yocum C. F. On the origin of light-induced changes in the proton magnetic relaxation rate of chloroplast thylakoid membrane suspensions. Arch Biochem Biophys. 1981 Mar;207(1):1–8. doi: 10.1016/0003-9861(81)90001-1. [DOI] [PubMed] [Google Scholar]
  12. Robinson H. H., Sharp R. R., Yocum C. F. Topology of NH2OH induced Mn(II) release from chloroplast thylakoid membranes. Biochim Biophys Acta. 1981 Jul;636(2):144–152. doi: 10.1016/0005-2728(81)90087-6. [DOI] [PubMed] [Google Scholar]
  13. Sharp R. R., Yocum C. F. Factors influencing hydroxylamine inactivation of photosynthetic water oxidation. Biochim Biophys Acta. 1981 Mar 12;635(1):90–104. doi: 10.1016/0005-2728(81)90010-4. [DOI] [PubMed] [Google Scholar]
  14. Sharp R. R., Yocum C. F. Field-dispersion profiles of the proton spin-lattice relaxation rate in chloroplast suspensions. Effect of manganese extraction by EDTA, Tris, and hydroxylamine. Biochim Biophys Acta. 1980 Aug 5;592(1):185–195. doi: 10.1016/0005-2728(80)90124-3. [DOI] [PubMed] [Google Scholar]
  15. Siderer Y., Malkin S., Poupko R., Luz Z. Electron spin resonance and photoreaction of Mn(II) in lettuce chloroplasts. Arch Biochem Biophys. 1977 Feb;179(1):174–182. doi: 10.1016/0003-9861(77)90101-1. [DOI] [PubMed] [Google Scholar]
  16. Warden J. T., Blankenship R. E., Sauer K. A flash photolysis ESR study of photosystem II signal IIvf, the physiological donor to P-680+. Biochim Biophys Acta. 1976 Mar 12;423(3):462–478. doi: 10.1016/0005-2728(76)90201-2. [DOI] [PubMed] [Google Scholar]
  17. Wydrzynski T., Sauer K. Periodic changes in the oxidation state of manganese in photosynthetic oxygen evolution upon illumination with flashes. Biochim Biophys Acta. 1980 Jan 4;589(1):56–70. doi: 10.1016/0005-2728(80)90132-2. [DOI] [PubMed] [Google Scholar]
  18. Wydrzynski T., Zumbulyadis N., Schmidt P. G., Gutowsky H. S., Govindjee Proton relaxation and charge accumulation during oxygen evolution in photosynthesis. Proc Natl Acad Sci U S A. 1976 Apr;73(4):1196–1198. doi: 10.1073/pnas.73.4.1196. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Yerkes C. T., Babcock G. T. Surface charge asymmetry and a specific calcium ion effect in chloroplast photosystem II. Biochim Biophys Acta. 1981 Jan 14;634(1):19–29. doi: 10.1016/0005-2728(81)90124-9. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES