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
. 1992 Jul 15;89(14):6497–6501. doi: 10.1073/pnas.89.14.6497

Photoinduced electron transfer from tris(2,2'-bipyridyl)ruthenium to cytochrome c oxidase.

T Nilsson 1
PMCID: PMC49528  PMID: 1321442

Abstract

Flash photolysis has been used to effect electron transfer from tris(2,2'-bipyridyl)ruthenium(II) to cytochrome c oxidase in the presence of a sacrificial electron donor, aniline. The observation that photoreduction occurs only at low ionic strength and high pH indicates that an electrostatic complex between the ruthenium compound and the enzyme is the reactive species. The reaction was followed at 830, 605, and 445 nm. The initial absorbance changes observed suggest that the copper ion CuA is the preferred electron acceptor and that electron transfer from the excited ruthenium complex takes place in less than 1 microsecond. Some rapid cytochrome a reduction is also observed. Absorbance changes after the initial transients suggest that the reduced CuA then equilibrates with cytochrome a with a rate constant of 2 x 10(4) s-1. Comparison of the absorbance changes at 605 and 445 nm and the kinetic difference spectrum in the Soret region indicate that no reduction of cytochrome a3 takes place. With the oxidized enzyme, no further reactions were detected, whereas, in the peroxide and ferryl intermediates, cytochrome a reoxidizes on a millisecond time scale. The reaction appears biphasic in both intermediates, with rate constants in the range 2 x 10(2) to 4 x 10(3) s-1. This is considerably slower than the maximal rates observed for electron transfer between cytochrome a and the bimetallic site found in earlier work and suggests rate limitation by other processes. The rates obtained for the slower phases are close to the rate for catalysis of cytochrome c oxidation.

Full text

PDF
6497

Selected References

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

  1. Baker G. M., Noguchi M., Palmer G. The reaction of cytochrome oxidase with cyanide. Preparation of the rapidly reacting form and its conversion to the slowly reacting form. J Biol Chem. 1987 Jan 15;262(2):595–604. [PubMed] [Google Scholar]
  2. Blair D. F., Bocian D. F., Babcock G. T., Chan S. I. Evidence for modulation of the heme absorptions of cytochrome c oxidase by metal-metal interactions. Biochemistry. 1982 Dec 21;21(26):6928–6935. doi: 10.1021/bi00269a048. [DOI] [PubMed] [Google Scholar]
  3. Blair D. F., Ellis W. R., Jr, Wang H., Gray H. B., Chan S. I. Spectroelectrochemical study of cytochrome c oxidase: pH and temperature dependences of the cytochrome potentials. Characterization of site-site interactions. J Biol Chem. 1986 Sep 5;261(25):11524–11537. [PubMed] [Google Scholar]
  4. Brandt U., Schägger H., von Jagow G. Purification of cytochrome-c oxidase retaining its pulsed form. Eur J Biochem. 1989 Jul 1;182(3):705–711. doi: 10.1111/j.1432-1033.1989.tb14882.x. [DOI] [PubMed] [Google Scholar]
  5. Chan S. I., Li P. M. Cytochrome c oxidase: understanding nature's design of a proton pump. Biochemistry. 1990 Jan 9;29(1):1–12. doi: 10.1021/bi00453a001. [DOI] [PubMed] [Google Scholar]
  6. Ellis W. R., Jr, Wang H., Blair D. F., Gray H. B., Chan S. I. Spectroelectrochemical study of the cytochrome a site in carbon monoxide inhibited cytochrome c oxidase. Biochemistry. 1986 Jan 14;25(1):161–167. doi: 10.1021/bi00349a023. [DOI] [PubMed] [Google Scholar]
  7. Greenwood C., Gibson Q. H. The reaction of reduced cytochrome C oxidase with oxygen. J Biol Chem. 1967 Apr 25;242(8):1782–1787. [PubMed] [Google Scholar]
  8. Hill B. C. The reaction of the electrostatic cytochrome c-cytochrome oxidase complex with oxygen. J Biol Chem. 1991 Feb 5;266(4):2219–2226. [PubMed] [Google Scholar]
  9. Kobayashi K., Une H., Hayashi K. Electron transfer process in cytochrome oxidase after pulse radiolysis. J Biol Chem. 1989 May 15;264(14):7976–7980. [PubMed] [Google Scholar]
  10. Mayo S. L., Ellis W. R., Jr, Crutchley R. J., Gray H. B. Long-range electron transfer in heme proteins. Science. 1986 Aug 29;233(4767):948–952. doi: 10.1126/science.3016897. [DOI] [PubMed] [Google Scholar]
  11. Michel B., Bosshard H. R. Spectroscopic analysis of the interaction between cytochrome c and cytochrome c oxidase. J Biol Chem. 1984 Aug 25;259(16):10085–10091. [PubMed] [Google Scholar]
  12. Moody A. J., Rich P. R. The effect of pH on redox titrations of haem a in cyanide-liganded cytochrome-c oxidase: experimental and modelling studies. Biochim Biophys Acta. 1990 Feb 2;1015(2):205–215. doi: 10.1016/0005-2728(90)90022-v. [DOI] [PubMed] [Google Scholar]
  13. Morgan J. E., Li P. M., Jang D. J., el-Sayed M. A., Chan S. I. Electron transfer between cytochrome a and copper A in cytochrome c oxidase: a perturbed equilibrium study. Biochemistry. 1989 Aug 22;28(17):6975–6983. doi: 10.1021/bi00443a030. [DOI] [PubMed] [Google Scholar]
  14. Oliveberg M., Hallén S., Nilsson T. Uptake and release of protons during the reaction between cytochrome c oxidase and molecular oxygen: a flow-flash investigation. Biochemistry. 1991 Jan 15;30(2):436–440. doi: 10.1021/bi00216a019. [DOI] [PubMed] [Google Scholar]
  15. Oliveberg M., Malmström B. G. Internal electron transfer in cytochrome c oxidase: evidence for a rapid equilibrium between cytochrome a and the bimetallic site. Biochemistry. 1991 Jul 23;30(29):7053–7057. doi: 10.1021/bi00243a003. [DOI] [PubMed] [Google Scholar]
  16. Pan L. P., Frame M., Durham B., Davis D., Millett F. Photoinduced electron transfer within complexes between plastocyanin and ruthenium bisbipyridine dicarboxybipyridine cytochrome c derivatives. Biochemistry. 1990 Apr 3;29(13):3231–3236. doi: 10.1021/bi00465a013. [DOI] [PubMed] [Google Scholar]
  17. Sinjorgo K. M., Steinebach O. M., Dekker H. L., Muijsers A. O. The effects of pH and ionic strength on cytochrome c oxidase steady-state kinetics reveal a catalytic and a non-catalytic interaction domain for cytochrome c. Biochim Biophys Acta. 1986 Jun 10;850(1):108–115. doi: 10.1016/0005-2728(86)90014-9. [DOI] [PubMed] [Google Scholar]
  18. Vygodina T. V., Konstantinov A. A. H2O2-induced conversion of cytochrome c oxidase peroxy complex to oxoferryl state. Ann N Y Acad Sci. 1988;550:124–138. doi: 10.1111/j.1749-6632.1988.tb35329.x. [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