TY - JOUR
T1 - Kinetics of electron transfer-induced conformational changes in cytochrome c immobilized on electrodes studied with surface plasmon resonance
AU - Boussaad, S.
AU - Tao, Nongjian
N1 - Funding Information:
We thank S. Wong, R. Arechabaleta, J.F. Pean for their help in the experiments and Drs S. Wang and Y. Zhang (Biochemistry Department, University of Miami) for their help in protein purification. We thank also Professor Jens Ulstrup and Professor Niki for valuable discussions. This work is supported by grants from NSF(CHE-9818073) and DOE(DE-FG03-01ER45943).
PY - 2003/9/15
Y1 - 2003/9/15
N2 - The electron transfer-induced conformational changes in cytochrome c adsorbed on electrodes have been studied with high-resolution surface plasmon resonance spectroscopy. The conformational changes in the native protein follow a stretched exponential function, exp[-(t/τ)0.5], suggesting a distribution of the activation barrier heights in the process. The measured time constants, τ, are 0.21 and 0.14 s for the oxidation and reduction, respectively. They are much slower than the electron transfer process, due to structural relaxation of the protein layer. As the concentration of guanidine hydrochloride is increased to 3 M, the conformational changes diminish, which indicates that the electron-transfer center is decoupled from the rest of the protein. After replacing the denaturant with buffer, the conformational changes re-appear but occur with much slower time constants. The slowing-down of the conformational changes may be due to the trapping of the protein in an intermediate state.
AB - The electron transfer-induced conformational changes in cytochrome c adsorbed on electrodes have been studied with high-resolution surface plasmon resonance spectroscopy. The conformational changes in the native protein follow a stretched exponential function, exp[-(t/τ)0.5], suggesting a distribution of the activation barrier heights in the process. The measured time constants, τ, are 0.21 and 0.14 s for the oxidation and reduction, respectively. They are much slower than the electron transfer process, due to structural relaxation of the protein layer. As the concentration of guanidine hydrochloride is increased to 3 M, the conformational changes diminish, which indicates that the electron-transfer center is decoupled from the rest of the protein. After replacing the denaturant with buffer, the conformational changes re-appear but occur with much slower time constants. The slowing-down of the conformational changes may be due to the trapping of the protein in an intermediate state.
KW - Protein folding
KW - Redox protein
KW - Surface plasmon
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U2 - 10.1016/S0022-0728(03)00197-9
DO - 10.1016/S0022-0728(03)00197-9
M3 - Article
AN - SCOPUS:0141636361
SN - 1572-6657
VL - 554-555
SP - 233
EP - 239
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
IS - 1
ER -