Electron-transfer mechanism of the triplet state quenching of aluminium tetrasulfonated phthalocyanine by cytochrome c

Biophysical Chemistry
César A T LaiaL F Vieira Ferreira

Abstract

The mechanism of electron-transfer from aluminium tetrasulfonated phthalocyanine triplet state to cytochrome c was investigated in this work. This reaction successfully quenches the dye triplet state due to the formation of complexes between the solute and the protein at the active site. The electron-transfer rate constant is around 3x10(7) s(-1), and is in accordance with previous results for the singlet excited state quenching [C.A.T. Laia, S.M.B. Costa, D. Phillips, A. Beeby. Electron-transfer kinetics in sulfonated aluminum phthalocyanines/cytochrome c complexes, J. Phys. Chem. B 108 (2004) 7506-7514.] in the framework of the Marcus theory, with a reorganization energy equal to 0.94 eV. The complex formation is diffusion controlled, but heterogeneities of the protein surface charge distribution lead to quenching rate constants smaller than predicted on a hard-spheres model with electrostatic interactions. Also the binding equilibrium constant is strongly affected by this phenomenon. Ionic strength plays an important role on the complex formation, but its effect on the unimolecular electron-transfer rate constant is negligible within experimental error.

References

Jul 20, 1992·Journal of Molecular Biology·G I Makhatadze, P L Privalov
Aug 28, 1998·Science·D R Green, J C Reed
Aug 15, 2001·European Journal of Biochemistry·F SinibaldiR Santucci
Dec 26, 2001·Chemical Reviews·M W Peczuh, A D Hamilton
Apr 10, 2003·Journal of the American Chemical Society·Andrew J WilsonAndrew D Hamilton
Jun 19, 2003·Journal of the American Chemical Society·Dimitri E KhoshtariyaDavid H Waldeck
Jul 23, 2003·Bioorganic & Medicinal Chemistry Letters·Toshihiro Aya, Andrew D Hamilton
Feb 6, 2004·Journal of Molecular Biology·Ivano BertiniGérard Simonneaux
Feb 12, 2004·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Luis F Vieira FerreiraAnabela S Oliveira
May 6, 2004·Journal of the American Chemical Society·Laura BaldiniAndrew D Hamilton
Mar 2, 2005·Proceedings of the National Academy of Sciences of the United States of America·Brian M HoffmanJudith M Nocek

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Citations

Mar 10, 2012·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Rehab M AminClaudia Scalfi-Happ

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