Premium
Electron Transfer and Electrocatalytic Properties of the Immobilized Met80Ala Cytochrome c Variant in Dimethylsulfoxide
Author(s) -
Di Rocco Giulia,
Bighi Beatrice,
Borsari Marco,
Bortolotti Carlo Augusto,
Ranieri Antonio,
Sola Marco,
Battistuzzi Gianantonio
Publication year - 2021
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.202100499
Subject(s) - chemistry , electron transfer , cytochrome c , electron transport chain , heme , ligand (biochemistry) , solvent , electrode , hydroxide , hemeprotein , crystallography , inorganic chemistry , photochemistry , organic chemistry , biochemistry , enzyme , mitochondrion , receptor
The electrode‐immobilized Met80Ala variant of yeast iso‐1 cytochrome c in mixed water/dimethylsulfoxide (DMSO) solutions up to 60 % v/v DMSO shows thermodynamic and kinetic parameters of electron exchange and electrocatalytic properties towards O 2 reduction fully comparable to those in water. This is the result of moderate protein conformational changes thanks to immobilization that, to a certain extent, preserves protein structure, possibly due to the constraints on protein mobility/flexibility induced by the electrostatic interactions with the electrode‐coating SAM. Upon increasing the DMSO content of the mixed solution beyond 60 %, a much larger perturbation occurs that leads to the progressive loss of the electrocatalytic ability. Therefore, under these conditions, the organic solvent remarkably affects the structure and properties of the protein probably involving major conformational changes or even the replacement of the 6 th axial hydroxide ligand of the heme iron with a strong protein ligand, possibly a lysine residue.