Voltammetry of a ‘protein on a rope’

FEBS Letters

Baymann, Frauke¹  Leroy, Gisele²  Aubert, Corinne²  Barlow, Nicola L¹  Schoepp-Cothenet, Barbara²  Armstrong, Fraser A¹ 

[1] Inorganic Chemistry Laboratory, South Parks Road, Oxford, UK;IBSM/CNRS Marseille, 31, Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France

关键词: Cytochrome;    Voltammetry;    Electron transfer;    Aquifex aeolicus;   

DOI  :  10.1016/S0014-5793(03)00206-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A periplasmic electron-transfer protein, cytochrome c ₅₅₅ ^m from Aquifex aeolicus contains a 62-residue N-terminal extension by which it is anchored to the membrane – most probably via a thioester bond to its N-terminal cysteine. This linker can act as a ‘rope’ to tether the protein close to its reaction partners. Mimicking this principle, a recombinant cytochrome c ₅₅₅ ^m, expressed in Escherichia coli, has been attached covalently to a gold electrode modified with 6-mercaptohexan-1-ol. The ‘tethered’ cytochrome c ₅₅₅ ^m displays remarkably fast electron-transfer kinetics, with an electrochemical exchange rate constant k ₀ of 1.4×10⁴ s⁻¹. The results show that fast electron transfer is associated with weak interactions: importantly, the tethered cytochrome can explore many different orientations without escaping into solution.

【 授权许可】

Unknown