Detection of an intermediate of photosynthetic water oxidation

Abstract

The oxygen that we breathe is produced by photosystem II of cyanobacteria and plants. The catalytic centre, a Mn4Ca cluster, accumulates four oxidizing equivalents before oxygen is formed, seemingly in a single reaction step1,2,3,4,5,6,7,8 2H2OO2 + 4H+ + 4e-. The energy and cycling of this reaction derives solely from light. No intermediate oxidation product of water has been detected so far. Here, we shifted the equilibrium of the terminal reaction backward by increasing the oxygen pressure and monitoring (by absorption transients in the near-ultraviolet spectrum) the electron transfer from bound water into the catalytic centre. A tenfold increase of ambient oxygen pressure (2.3 bar) half-suppressed the full progression to oxygen. The remaining electron transfer at saturating pressure (30 bar) was compatible with the formation of a stabilized intermediate. The abstraction of four electrons from water was probably split into at least two electron transfers: mildly endergonic from the centre's highest oxidation state to an intermediate, and exergonic from the intermediate to oxygen. There is little leeway for photosynthetic organisms to push the atmospheric oxygen concentration much above the present level.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Ultraviolet absorption transients at a wavelength of 360 nm of dark-adapted PSII core particles under excitation with five short laser flashes (arrows).
Figure 2: Ultraviolet absorption transients as induced by the second and third flash under variation of the gas composition and pressure.
Figure 3: Electron transfer into the catalytic Mn4Ca centre at three different oxygen pressures, and corrected ultraviolet absorption transients at the third flash.
Figure 4: Titration of the corrected absorption transients by elevated oxygen pressure (see text and equation (4)).

References

  1. 1

    Barber, J. Photosystem II: the engine of life. Q. Rev. Biophys. 36, 71–89 (2003)

    CAS  Article  Google Scholar 

  2. 2

    Renger, G. Photosynthetic water oxidation to molecular oxygen: apparatus and mechanism. Biochim. Biophys. Acta 1503, 210–228 (2001)

    CAS  Article  Google Scholar 

  3. 3

    Robblee, J. H., Cinco, R. M. & Yachandra, V. K. X-ray spectroscopy-based structure of the Mn cluster and mechanism of photosynthetic oxygen evolution. Biochim. Biophys. Acta 1503, 7–23 (2001)

    CAS  Article  Google Scholar 

  4. 4

    Zouni, A. et al. Crystal structure of photosystem II from Synechococcus elongatus at 3.8 Å resolution. Nature 409, 739–743 (2001)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Kamiya, N. & Shen, J. R. Crystal structure of oxygen-evolving photosystem II from Thermosynechococcus vulcanus at 3.7-angstrom resolution. Proc. Natl Acad. Sci USA 100, 98–103 (2003)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Ferreira, K. N., Iverson, T. M., Maghlaoui, K., Barber, J. & Iwata, S. Architecture of the photosynthetic oxygen-evolving center. Science 303, 1831–1838 (2004)

    ADS  CAS  Article  Google Scholar 

  7. 7

    Rutherford, A. W. Photosystem II, the water-splitting enzyme. Trends Biochem. Sci. 14, 227–232 (1989)

    CAS  Article  Google Scholar 

  8. 8

    Kok, B., Forbush, B. & McGloin, M. Cooperation of charges in photosynthetic O2 evolution - I. A linear four-step mechanism. Photochem. Photobiol. 11, 457–475 (1970)

    CAS  Article  Google Scholar 

  9. 9

    Hendry, G. & Wydrzynski, T. O-18 isotope exchange measurements reveal that calcium is involved in the binding of one substrate-water molecule to the oxygen-evolving complex in photosystem II. Biochemistry 42, 6209–6217 (2003)

    CAS  Article  Google Scholar 

  10. 10

    Hillier, W., Messinger, J. & Wydrzynski, T. Kinetic determination of the fast exchanging substrate water molecule in the S3 state of photosystem II. Biochemistry 37, 16908–16914 (1998)

    CAS  Article  Google Scholar 

  11. 11

    Renger, G. in Photosynthetic Oxygen Evolution (ed. Metzner, H.) 229–248 (Academic, London, 1978)

    Google Scholar 

  12. 12

    Clausen, J., Debus, R. J. & Junge, W. Time-resolved oxygen production by PSII: Chasing chemical intermediates. Biochim. Biophys. Acta 1655, 184–194 (2004)

    CAS  Article  Google Scholar 

  13. 13

    Babcock, G. T., Blankenship, R. E. & Sauer, K. Reaction kinetics for positive charge accumulation on the water side of chloroplast photosystem II. FEBS Lett. 61, 286–289 (1976)

    CAS  Article  Google Scholar 

  14. 14

    Dekker, J. P., Plijter, J. J., Ouwehand, L. & van Gorkom, H. J. Kinetics of manganese redox transitions in the oxygen evolving apparatus of photosynthesis. Biochim. Biophys. Acta 767, 176–179 (1984)

    CAS  Article  Google Scholar 

  15. 15

    Renger, G. & Weiss, W. Studies on the nature of the water oxidizing enzyme. III. Spectral characterization of the intermediary redox states in the water-oxidizing enzyme system Y. Biochim. Biophys. Acta 850, 184–196 (1986)

    CAS  Article  Google Scholar 

  16. 16

    Saygin, Ö. & Witt, H. T. Optical characterization of intermediates in the water-splitting enzyme system of photosynthesis—possible states and configurations of manganese and water. Biochim. Biophys. Acta 893, 452–469 (1987)

    CAS  Article  Google Scholar 

  17. 17

    Haumann, M., Bögershausen, O., Cherepanov, D. A., Ahlbrink, R. & Junge, W. Photosynthetic oxygen evolution: H/D isotope effects and the coupling between electron and proton transfer during the redox reactions at the oxidizing side of photosystem II. Photosynth. Res. 51, 193–208 (1997)

    CAS  Article  Google Scholar 

  18. 18

    Hundelt, M., Hays, A. M., Debus, R. J. & Junge, W. Oxygenic photosystem II: the mutation D1-D61N in Synechocystis sp. PCC 6803 retards S-state transitions without affecting electron transfer from YZ to P680+. Biochemistry 37, 14450–14456 (1998)

    CAS  Article  Google Scholar 

  19. 19

    Karge, M., Irrgang, K. D. & Renger, G. Analysis of the reaction coordinate of photosynthetic water oxidation by kinetic measurements of 355 nm absorption changes at different temperatures in photosystem II preparations suspended in either H2O or D2O. Biochemistry 36, 8904–8913 (1997)

    CAS  Article  Google Scholar 

  20. 20

    Rappaport, F., Blanchard-Desce, M. & Lavergne, J. Kinetics of electron transfer and electrochromic change during the redox transition of the photosynthetic oxygen-evolving complex. Biochim. Biophys. Acta 1184, 178–192 (1994)

    CAS  Article  Google Scholar 

  21. 21

    Clausen, J. et al. Photosynthetic water oxidation: Mutations of D1-Glu189K, R and Q of Synechocystis sp. PCC6803 are without any influence on electron transfer rates at the donor side of photosystem II. Biochim. Biophys. Acta 1506, 224–235 (2001)

    CAS  Article  Google Scholar 

  22. 22

    Lavergne, J. Improved UV-visible spectra of the S-transitions in the photosynthetic oxygen-evolving system. Biochim. Biophys. Acta 1060, 175–188 (1991)

    CAS  Article  Google Scholar 

  23. 23

    Dekker, J. P. in Manganese Redox Enzymes (ed. Pecoraro, V. L.) 85–104 (VCH Publishers, New York, 1992)

    Google Scholar 

  24. 24

    Haumann, M., Drevenstedt, W., Hundelt, M. & Junge, W. Photosystem II of green plants: Oxidation and deprotonation of the same component (histidine?) on S1* → S2* in chloride depleted centers as on S2 → S3 in controls. Biochim. Biophys. Acta 1273, 237–250 (1996)

    Article  Google Scholar 

  25. 25

    Rappaport, F. & Lavergne, J. Coupling of electron and proton transfer in the photosynthetic water oxidase. Biochim. Biophys. Acta 1503, 246–259 (2001)

    CAS  Article  Google Scholar 

  26. 26

    Jahns, P., Lavergne, J., Rappaport, F. & Junge, W. Stoichiometry of proton release during photosynthetic water oxidation: a reinterpretation of the response of Neutral red leads to a non-integer pattern. Biochim. Biophys. Acta 1057, 313–319 (1991)

    CAS  Article  Google Scholar 

  27. 27

    Lavergne, J. & Junge, W. Proton release during the redox cycle of the water oxidase. Photosynth. Res. 38, 279–296 (1993)

    CAS  Article  Google Scholar 

  28. 28

    Junge, W., Haumann, M., Ahlbrink, R., Mulkidjanian, A. & Clausen, J. Electrostatics and proton transfer in photosynthetic water oxidation. Phil. Trans. R. Soc. Lond. B 357, 1407–1417 (2002)

    CAS  Article  Google Scholar 

  29. 29

    Beck, W. F., de Paula, J. C. & Brudvig, G. W. Active and resting state of the O2-evolving complex of Photosystem II. Biochemistry 24, 3035–3043 (1985)

    CAS  Article  Google Scholar 

  30. 30

    Klimov, V. V., Allakhverdiev, S. I., Demeter, S. & Krasnovsky, A. A. Photoreduction of pheophytin in the photosystem II of chloroplasts with respect to the redox potential of the medium. Dokl. Akad. Nauk SSSR 249, 227–230 (1979)

    CAS  Google Scholar 

Download references

Acknowledgements

We thank H. Kenneweg for technical assistance, H. Heine for advice on the construction of the pressure cell, R. Debus for cooperation on Synechocystis, and R. Ahlbrink and A. Mulkidjanian for discussions and help. This work was financially supported by the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie and the Land Niedersachsen.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Wolfgang Junge.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Clausen, J., Junge, W. Detection of an intermediate of photosynthetic water oxidation. Nature 430, 480–483 (2004). https://doi.org/10.1038/nature02676

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing