Ubiquinol-cytochrome c reductase (Complex III) electrochemistry at multi-walled carbon nanotubes/Nafion modified glassy carbon electrodes

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• 作者：Lindsey N. Pelster ; Shelley D. Minteer
• 关键词：Ubiquinol-cytochrome c reductase ; Electron transport chain ; Bioelectrocatalysis ; Cytochrome c
• 刊名：Electrochimica Acta
• 出版年：2012
• 出版时间：1 November, 2012
• 年：2012
• 卷：82
• 期：Complete
• 页码：214-217
• 全文大小：521 K

文摘

Electron transport chain complexes are critical to metabolism in living cells. Ubiquinol-cytochrome c reductase (Complex III) is responsible for carrying electrons from ubiquinol to cytochrome c, but the complex has not been evaluated electrochemically. This work details the bioelectrochemistry of ubiquinol-cytochrome c reductase of the electron transport chain of tuber mitochondria. The characterization of the electrochemistry of this enzyme is investigated in carboxylated multi-walled carbon nanotube/tetrabutyl ammonium bromide-modified Nafion^? modified glassy carbon electrodes by cyclic voltammetry. Increasing concentrations of cytochrome c result in a catalytic response from the active enzyme in the nanotube sandwich. The experiments show that the enzyme followed Michaelis-Menten kinetics with a K_m for the immobilized enzyme of 2.97 (¡À0.11) ¡Á 10^?6 M and a V_max of 6.31 (¡À0.82) ¡Á 10^?3 ¦Ìmol min^?1 at the electrode, but the K_m and V_max values decreased compared to the free enzyme in solution, which is expected for immobilized redox proteins. This is the first evidence of ubiquinol-cytochrome c reductase bioelectrocatalysis.