Advertisement

Anisotropic Magnetic Field Effects of the Photosynthetic Bacterial Reaction Center of Rhodobacter sphaeroides R-26, Studied by Linear Dichroic Magneto-optical Difference Spectroscopy (LD-MODS) in the Temperature Range 1.2 – 310 K

  • E. J. Lous
  • A. J. Hoff
Chapter
Part of the NATO ASI Series book series (NSSA, volume 149)

Abstract

Recently we have introduced magneto-optical difference spectroscopy (MODS) to measure triplet-minus-singlet absorbance difference (T – S) spectra of bacterial photosynthetic reaction centers (RC) over a wide range of temperatures (Hoff et al., 1985; Lous and Hoff, 1986). The MODS technique rests upon the change in yield of the triplet state of the primary donor, 3P, effected by a magnetic field of small amplitude (a few tens of millitesla). The field is modulated at a few hundred hertz and the resulting modulation in absorbance lock-in detected over a wide range of wavelengths. Since the magnetic field BO is a vectorial quantity and the magnetic field effect (MFE) sensitive to the orientation of RC with respect to \( {\vec B_O} \) (see below), one expects that it should be possible to perform a linear dichroic (LD)-MODS experiment, which would result in a LD-(T – S) spectrum. Knowledge of the orientational dependence of the MFE should then allow to extract information on e.g. the magnitude and direction of the dipolar interaction of the primary radical pair (RP) P+I, where I is the bacteriopheophytin acceptor. The dipolar interaction between P+ and I plays a significant role in the interpretation of reaction yield detected magnetic resonance (RYDMR) and MFE spectra (Lersch and Michel-Beyerle, 1982; Tang and Norris, 1983; Moehl et al., 1985; Hunter et al., 1987). An independent determination of the dipolar interaction would help in obtaining a reliable value of the isotropic exchange interaction J(P+I), which is of great interest for understanding photoinduced electron transport (Marcus, 1987; Bixon, 1987).

Keywords

Triplet State Photosynthetic Bacterium Magnetic Field Effect Photosynthetic Reaction Center Linear Dichroic 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bixon, M., Jortner, J., Michel-Beyerle, M.E., Ogrodnik, A., and Lersch. W., 1987, On the role of the accessory bacterioclorophyll in reaction centers of photosynthetic bacteria: Intermediate acceptors in the primary electron transfer, Chem. Phys. Lett., in the press.Google Scholar
  2. Boxer, S.G., Chidsey, C.E.D., and Roelofs, M.G., 1983 Magnetic field effects in the solid state: An example from photosynthetic reaction centers. Ann. Rev. Phys. Chem. 34:389.CrossRefGoogle Scholar
  3. Chidsey, C.E.D., Kirmaier, C, Holten, D., and Boxer, S.G., 1984 Magnetic field dependence of radical-pair decay kinetics and molecular triplet quantum yield in quinone-depleted reaction centers, Biochim. Biophys. Acta 766:424.CrossRefGoogle Scholar
  4. Chidsey, C.E.D., Takiff, L., Goldstein, R.A., and Boxer, S.G., 1985 Effect of magnetic fields on the triplet state lifetime in photosynthetic reaction centers: Evidence for thermal repopulation of the initial radical pair, Proc. Natl. Acad. Sci. USA 82:6850.PubMedCrossRefGoogle Scholar
  5. Clarke, R.H., Connors, R.E., and Keegan, J., 1977 Magnetic field effect on the low temperature triplet state population of an organic molecule, J. Chem. Phys. 66:3.58.CrossRefGoogle Scholar
  6. De Vries, H.G., and Hoff, A.J., 1978 Magnetic field effect on the fluorescence intensity of Rhodopseudomonas sphaeroides at 1.4 K, Chem. Phys. Lett. 55:395.CrossRefGoogle Scholar
  7. Den Blanken, H.J., and Hoff, A.J., 1982 High-resolution optical absorption-difference spectra of the triplet state of the primary donor in isolated reaction centers of the photosynthetic bacteria Rhodopseudomonas sphaeroides R-26 and Rhodopseudomonas viridis measured with optically detected magnetic resonance at 1.2 K, Biochim. Biophys. Acta 681:365.CrossRefGoogle Scholar
  8. Den Blanken, H.J., Meiburg, R.F., and Hoff, A.J., 1984 Polarized tripletminus-singlet absorbance difference spectra measured by absorbance-detected magnetic resonance (ADMR), Chem. Phys. Lett. 105:336.CrossRefGoogle Scholar
  9. Haberkorn, R., and Michel-Beyerle, M.E., 1979 On the mechanism of magnetic field effects in bacterial photosynthesis, Biophys. J. 26:489.PubMedCrossRefGoogle Scholar
  10. Hoff, A.J., 1976 Kinetics of populating and depopulating of the photoinduced triplet state of the photosynthetic bacteria Rhodospirillum rubrum, Rhodopseudomonas sphaeorides (wild type), and its mutant R-26 as measured by ESR in zero-field, Biochim. Biophys. Acta 440:765.PubMedCrossRefGoogle Scholar
  11. Hoff, A.J., Rademaker, H., van Grondelle, R., and Duysens, L.N.M., 1977 On the magnetic field dependence of the triplet state in reaction centers of photosynthetic bacteria, Biochim. Biophys. Acta 460:547.PubMedCrossRefGoogle Scholar
  12. Hoff, A.J., and de Vries, H.G., 1978 Electron spin resonance in zero magnetic field of the reaction center triplet of photosynthetic bacteria, Biochim. Biophys. Acta 503:94.PubMedCrossRefGoogle Scholar
  13. Hoff, A.J., 1979 Application of ESR in photosynthesis, Phys. Reports 54:75.CrossRefGoogle Scholar
  14. Hoff, A.J., 1981 Magnetic field effects on photosynthetic reaction, Quart. Rev. Biophys. 14:599.CrossRefGoogle Scholar
  15. Hoff, A.J., 1982, ODMR spectroscopy in photosynthesis II, in: ‘Triplet state ODMR Spectroscopy’, R.H. Clarke, ed., John Wiley & Sons, New York.Google Scholar
  16. Hoff, A.J., and Proskuryakov, I.I., 1985 Triplet EPR spectra of the primary electron donor in bacterial photosynthesis at temperatures between 15 and 296 K, Chem. Phys. Lett. 115:303.CrossRefGoogle Scholar
  17. Hoff, A.J., Lous, E.J., Moehl, K.W., and Dijkman, J.A., 1985 Magneto-optical absorbance difference spectroscopy. A new tool for the study of radical recombination reactions. An application to bacterial photosynthesis. Chem. Phys. Lett. 114:39.CrossRefGoogle Scholar
  18. Hore, P.J., Watson, E.T., Pedersen, J.B., and Hoff, A.J., 1986 Line-shape analysis of polarized electron paramagnetic resonance spectra of the primary reactants of bacterial photosynthesis. Biochim. Biophys. Acta 849:70.CrossRefGoogle Scholar
  19. Hunter, D.A., Hoff, A.J., and Hore, P.J., 1987 Theoretical calculations of RYDMR effects in photosynthetic bacteria, Chem. Phys. Lett. 134:6.CrossRefGoogle Scholar
  20. Kottis, P., and Lefebvre, R., 1963 Calculation of the electron spin resonance line shape of randomly oriented molecules in a triplet state. I. The Δm = 2 transition with a constant linewidth. J. Chem. Phys. 39:393.CrossRefGoogle Scholar
  21. Lersch, W., 1982, Zur spinselektiven Rekombination von Elektron-Loch-Paaren im bakteriellen Reaktionszentrum. Einfluss von Mikrowellen und anisotropen Wechselwirkungen auf die Spindynamik in äusseren Magnetfeldern, Diplomarbeit, München.Google Scholar
  22. Lersch, W., and Michel-Beyerle, M.E., 1983 Magnetic field effects on the recombination of radical ions in reaction centers of photosynthetic bacteria, Chem. Phys. 78:115.CrossRefGoogle Scholar
  23. Lous, E.J., and Hoff, A.J., 1986 Triplet-minus-singlet absorbance difference spectra of reaction centers of Rhodopseudomonas sphaeroides R-26 in the temperature range 24–290 K measured by Magneto-Optical Difference Spectroscopy (MODS), Photoynth. Res. 9:89.CrossRefGoogle Scholar
  24. Lous, E.J., and Hoff, A.J., 1987 Exciton interactions in reaction centers of the photosynthetic bacterium Rhodopseudomonas viridis probed by optical triplet-minus-singlet polarization spectroscopy at 1.2 K monitored through absorbance-detected magnetic resonance, Proc. Natl. Acad. Sci. USA 84:6147.PubMedCrossRefGoogle Scholar
  25. Marcus, R.A., 1987 Superexchange versus an intermediate bacteriochlorophyll mechanism in reaction centers of photosynthetic bacteria, Chem. Phys. Lett. 133:471.CrossRefGoogle Scholar
  26. Meiburg, R.F., 1985, Orientation of components and vectorial properties of photosynthetic reaction centers, Thesis, University of Leiden, The Netherlands.Google Scholar
  27. Moehl, K.W., Lous, E.J., and Hoff, A.J., 1985, Low-power, low-field RYDMAR of the primary radical pair in photosynthesis, Chem. Phys. Lett. 121: 22.CrossRefGoogle Scholar
  28. Norris, J.R., and van Brakel, G., 1986, Energy trapping in photosynthesis and purple bacteria, in: ‘Light Emission by Plants and Bacteria’, Govindjee, J. Amesz and D.C. Fork, eds., Acad. Press, New York.Google Scholar
  29. Ogrodnik, A., Remy-Richter, N., Michel-Beyerle, M.E., and Ficke, R., 1987, Chem. Phys. Lett., in the press.Google Scholar
  30. Schadee, R.A., Schmidt, J., and van der Waals, J.H., 1976 Intersystem crossing into a superposition of spin states? The system tetramethylpyrazine in durene, Chem. Phys. Lett. 41:435.CrossRefGoogle Scholar
  31. Scherer, P.O.J., Fischer, S.F., Hörber, J.K.H., and Michel-Beyerle, M.E., 1985, On the temperature-dependence of the long wavelength fluorescence and absorption of Rhodopseudomonas viridis reaction centers, in: ‘Antennas and Reaction Centers of Photosynthetic Bacteria. Structure, Interactions, and Dynamics’, M.E. Michel-Beyerle, ed., Springer-Verlag, Berlin.Google Scholar
  32. Tang, J., and Norris, J.R., 1983 Theoretical calculations of microwave effects on the triplet yield in photosynthetic reaction centers, Chem. Phys. Lett. 94:77.CrossRefGoogle Scholar
  33. Vermeglio, A., Breton, J., Paillotin, G., and Cogdell, R., 1978 Orientation of chromophores in reaction centers of Rhodopseudomonas sphaeroides: A photoselection study, Biochim. Biophys. Acta 501:514.PubMedCrossRefGoogle Scholar
  34. Wraight, C.A., Leigh, J.S., Dutton, P.L., and Clayton, R.K., 1974 The triplet state of reaction center bacteriochlorophyll: Determination of a relative quantum yield, Biochim. Biophys. Acta 333:401.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • E. J. Lous
    • 1
  • A. J. Hoff
    • 1
  1. 1.Department of Biophysics, Huygens LaboratoryState University of LeidenThe Netherlands

Personalised recommendations