Skip to main content
NCBI 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
. 1971 Jan;68(1):68–71. doi: 10.1073/pnas.68.1.68

Proton Magnetic Resonance Studies of the Ferredoxins from Spinach and Parsley

M Poe *, W D Phillips *, J D Glickson *, C C McDonald *, A San Pietro *
PMCID: PMC391104  PMID: 4322266

Abstract

Contact-shifted resonances have been detected in the pmr spectra of both oxidized and reduced forms of spinach and parsley ferredoxins. These resonances are assigned to the β-CH2 protons of four cysteine residues that are thought to bind the iron-sulfur redox center to the polypeptide chain. Temperature dependences of contact shifts reveal that the two iron atoms are antiferromagnetically coupled in both redox forms of each of these proteins. Thermal population of magnetic states gives rise to the contact shifts observed in the formally diamagnetic oxidized forms of these ferredoxins and accounts for the failure of contact shifts in the reduced forms exhibit to a Curie Law temperature dependence. It appears that the unpaired electron of reduced spinach and parsley ferredoxin is unequally distributed over the two iron centers. Valence states for the iron pairs of high-spin Fe+3-Fe+3 and Fe+2-Fe+3 for the oxidized and reduced forms, respectively, are compatible with the nmr results.

Full text

PDF
68

Selected References

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

  1. Brintzinger H., Palmer G., Sands R. H. On the ligand field of iron in ferredoxin from spinach chloroplasts and related nonheme iron enzymes. Proc Natl Acad Sci U S A. 1966 Feb;55(2):397–404. doi: 10.1073/pnas.55.2.397. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. FRY K. T., LAZZARINI R. A., SANPIETRO A. THE PHOTOREDUCTION OF IRON IN PHOTOSYNTHETIC PYRIDINE NUCLEOTIDE REDUCTASE. Proc Natl Acad Sci U S A. 1963 Oct;50:652–657. doi: 10.1073/pnas.50.4.652. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Gibson J. F., Hall D. O., Thornley J. H., Whatley F. R. The iron complex in spinach ferredoxin. Proc Natl Acad Sci U S A. 1966 Sep;56(3):987–990. doi: 10.1073/pnas.56.3.987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Keresztes-Nagy S., Margoliash E. Preparation and characterization of alfalfa ferredoxin. J Biol Chem. 1966 Dec 25;241(24):5955–5966. [PubMed] [Google Scholar]
  5. Kurland R. J., Davis D. G., Ho C. Paramagnetic proton nuclear magnetic resonance shifts of metmyoglobin, methemoglobin, and hemin derivatives. J Am Chem Soc. 1968 May 8;90(10):2700–2701. doi: 10.1021/ja01012a048. [DOI] [PubMed] [Google Scholar]
  6. Matsubara H., Sasaki R. M., Chain R. K. The amino Acid sequence of spinach ferredoxin. Proc Natl Acad Sci U S A. 1967 Feb;57(2):439–445. doi: 10.1073/pnas.57.2.439. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Moss T. H., Petering D., Palmer G. The magnetic susceptibility of oxidized and reduced ferredoxins from spinach and parsley and the high potential protein from Chromatium. J Biol Chem. 1969 May 10;244(9):2275–2277. [PubMed] [Google Scholar]
  8. Orme-Johnson W. H., Beinert H. Reductive titrations of iron-sulfur proteins containing two to four iron atoms. J Biol Chem. 1969 Nov 25;244(22):6143–6148. [PubMed] [Google Scholar]
  9. Palmer G., Sands R. H. On the magnetic resonance of spinach ferredoxin. J Biol Chem. 1966 Jan 10;241(1):253–253. [PubMed] [Google Scholar]
  10. Phillips W. D., Poe M., McDonald C. C., Bartsch R. G. Proton magnetic resonance studies of Chromatium high-potential iron protein. Proc Natl Acad Sci U S A. 1970 Oct;67(2):682–687. doi: 10.1073/pnas.67.2.682. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Phillips W. D., Poe M., Weiher J. F., McDonald C. C., Lovenberg W. Proton magnetic resonance, magnetic susceptibility and Mössbauer studies of Clostridium pasteurianum rubredoxin. Nature. 1970 Aug 8;227(5258):574–577. doi: 10.1038/227574a0. [DOI] [PubMed] [Google Scholar]
  12. Poe M., Phillips W. D., McDonald C. C., Lovenberg W. Proton magnetic resonance study of ferredoxin from Clostridium pasteurianum. Proc Natl Acad Sci U S A. 1970 Apr;65(4):797–804. doi: 10.1073/pnas.65.4.797. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Tagawa K., Arnon D. I. Oxidation-reduction potentials and stoichiometry of electron transfer in ferredoxins. Biochim Biophys Acta. 1968 Apr 2;153(3):602–613. doi: 10.1016/0005-2728(68)90188-6. [DOI] [PubMed] [Google Scholar]
  14. Thornley J. H., Gibson J. F., Whatley F. R., Hall D. O. Comment on a recent model of the iron complex in spinach ferredoxin. Biochem Biophys Res Commun. 1966 Sep 22;24(6):877–879. doi: 10.1016/0006-291x(66)90330-5. [DOI] [PubMed] [Google Scholar]
  15. Wüthrich K., Shulman R. G., Yamane T., Wyluda B. J., Hugli T. E., Gurd F. R. High resolution proton magnetic resonance studies of cyanoferrimyoglobins and alkylated derivatives from different species. J Biol Chem. 1970 Apr 25;245(8):1947–1953. [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