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
. 1979 Nov;76(11):5636–5640. doi: 10.1073/pnas.76.11.5636

Chromophore organization in photosynthetic reaction centers: High-resolution magnetophotoselection

Steven G Boxer 1, Mark G Roelofs 1
PMCID: PMC411704  PMID: 16592720

Abstract

The electron spin resonance spectrum of the triplet excited state of Rhodopseudomonas spheroides R-26 reaction centers has been studied after excitation with the polarized narrow-bandwidth output of a tunable dye laser from 520 to 670 nm. A theory is developed relating experimental observables to the angles between the electronic transition dipole moment of the excited chromophore and the principle magnetic axis system of the triplet state of the dimeric trap. Data is presented which demonstrates that the treatment is correct and useful, and angles are obtained for the Qx transitions of bacteriopheophytin. High-resolution magnetophotoselection data in the region of the bacteriochlorophyll Qx transitions can be combined with polarized photobleaching experiments to provide direct information on the structure of dimeric trap.

Keywords: chlorophyll, bacteriochlorophyll, dye laser, electron spin resonance, triplet

Full text

PDF
5636

Selected References

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

  1. Clayton R. K., Rafferty C. N., Vermeglio A. The orientations of transition moments in reaction centers of Rhodopseudomonas sphaeroides, computed from data of linear dichroism and photoselection measurements. Biochim Biophys Acta. 1979 Jan 11;545(1):58–68. doi: 10.1016/0005-2728(79)90113-0. [DOI] [PubMed] [Google Scholar]
  2. Dutton P. L., Leigh J. S., Jr, Reed D. W. Primary events in the photosynthetic reaction centre from Rhodopseudomonas spheroides strain R26: triplet and oxidized states of bacteriochlorophyll and the identification of the primary electron acceptor. Biochim Biophys Acta. 1973 Apr 5;292(3):654–664. doi: 10.1016/0005-2728(73)90013-3. [DOI] [PubMed] [Google Scholar]
  3. Fajer J., Brune D. C., Davis M. S., Forman A., Spaulding L. D. Primary charge separation in bacterial photosynthesis: oxidized chlorophylls and reduced pheophytin. Proc Natl Acad Sci U S A. 1975 Dec;72(12):4956–4960. doi: 10.1073/pnas.72.12.4956. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Feher G., Hoff A. J., Isaacson R. A., Ackerson L. C. ENDOR experiments on chlorophyll and bacteriochlorophyll in vitro and in the photosynthetic unit. Ann N Y Acad Sci. 1975 Apr 15;244:239–259. doi: 10.1111/j.1749-6632.1975.tb41534.x. [DOI] [PubMed] [Google Scholar]
  5. Kaufmann K. J., Dutton P. L., Netzel T. L., Leigh J. S., Rentzepis P. M. Picosecond kinetics of events leading to reaction center bacteriochlorophyll oxidation. Science. 1975 Jun 27;188(4195):1301–1304. doi: 10.1126/science.188.4195.1301. [DOI] [PubMed] [Google Scholar]
  6. Norris J. R., Uphaus R. A., Crespi H. L., Katz J. J. Electron spin resonance of chlorophyll and the origin of signal I in photosynthesis. Proc Natl Acad Sci U S A. 1971 Mar;68(3):625–628. doi: 10.1073/pnas.68.3.625. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Parson W. W., Clayton R. K., Cogdell R. J. Excited states of photosynthetic reaction centers at low recox potentials. Biochim Biophys Acta. 1975 May 15;387(2):265–278. doi: 10.1016/0005-2728(75)90109-7. [DOI] [PubMed] [Google Scholar]
  8. Rafferty C. N., Clayton R. K. Linear dichroism and the orientation of reaction centers of Rhodopseudomonas sphaeroides in dried gelatin films. Biochim Biophys Acta. 1979 Jan 11;545(1):106–121. doi: 10.1016/0005-2728(79)90118-x. [DOI] [PubMed] [Google Scholar]
  9. Rafferty C. N., Clayton R. K. Properties of reaction centers of Rhodopseudomonas sphaeroides in dried gelatin films. Linear dichroism and low temperature spectra. Biochim Biophys Acta. 1978 Apr 11;502(1):51–60. doi: 10.1016/0005-2728(78)90131-7. [DOI] [PubMed] [Google Scholar]
  10. Rafferty C. N., Clayton R. K. The orientations of reaction center transition moments in the chromatophore membrane of Rhodopseudomonas sphareroides, bases on new linear dichroism and photoselection measurements. Biochim Biophys Acta. 1979 May 9;546(2):189–206. doi: 10.1016/0005-2728(79)90039-2. [DOI] [PubMed] [Google Scholar]
  11. Rockley M. G., Windsor M. W., Cogdell R. J., Parson W. W. Picosecond detection of an intermediate in the photochemical reaction of bacterial photosynthesis. Proc Natl Acad Sci U S A. 1975 Jun;72(6):2251–2255. doi: 10.1073/pnas.72.6.2251. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Shuvalov V. A., Asadov A. A. Arrangement and interaction of pigment molecules in reaction centers of Rhodopseudomonas viridis. Photodichroism and circular dichroism of reaction centers at 100 k. Biochim Biophys Acta. 1979 Feb 8;545(2):296–308. doi: 10.1016/0005-2728(79)90207-x. [DOI] [PubMed] [Google Scholar]
  13. Thurnauer M. C., Katz J. J., Norris J. R. The triplet state in bacterial photosynthesis: Possible mechanisms of the primary photo-act. Proc Natl Acad Sci U S A. 1975 Sep;72(9):3270–3274. doi: 10.1073/pnas.72.9.3270. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Thurnauer M. C., Norris J. R. Magnetophotoselection applied to the triplet state observed by EPR in photosynthetic bacteria. Biochem Biophys Res Commun. 1976 Nov 22;73(2):501–506. doi: 10.1016/0006-291x(76)90735-x. [DOI] [PubMed] [Google Scholar]
  15. Vermeglio A., Breton J., Paillotin G., Cogdell R. Orientation of chromophores in reaction centers of Rhodopseudomonas sphaeroides: a photoselection study. Biochim Biophys Acta. 1978 Mar 13;501(3):514–530. doi: 10.1016/0005-2728(78)90118-4. [DOI] [PubMed] [Google Scholar]
  16. Werner H. J., Schulten K., Weller A. Electron transfer and spin exchange contributing to the magnetic field dependence of the primary photochemical reaction of bacterial photosynthesis. Biochim Biophys Acta. 1978 May 10;502(2):255–268. doi: 10.1016/0005-2728(78)90047-6. [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