کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5372451 | 1388881 | 2006 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electron-transfer mechanism of the triplet state quenching of aluminium tetrasulfonated phthalocyanine by cytochrome c
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
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 3 Ã 107 sâ 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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biophysical Chemistry - Volume 122, Issue 2, 20 July 2006, Pages 143-155
Journal: Biophysical Chemistry - Volume 122, Issue 2, 20 July 2006, Pages 143-155
نویسندگان
César A.T. Laia, SÃlvia M.B. Costa, L.F. Vieira Ferreira,