Cytochrome c Mutants for Superoxide Biosensors
Title:
Cytochrome c Mutants for Superoxide Biosensors
Authors:
Abstract:
The effect of introducing positive charges (lysines) in human cytochrome c (cyt c) on the redox properties and reaction rates of cyt c with superoxide radicals was studied. The mutated forms of this electron-transfer protein are used as sensorial recognition elements for the amperometric detection of the reactive oxygen radical. The proteins were prepared by site-directed mutagenesis focusing on amino acids near the heme edge. The 11 mutants of human cyt c expressed in the course of this research have been characterized by UV−vis spectroscopy, circular dichroism, and NMR spectroscopy to verify overall structure integrity as well as axial coordination of the heme iron. The mutants are investigated voltammetrically using promoter-modified gold electrodes with respect to redox activity and formal redox potential. The rate constants for the reaction with superoxide have been determined spectrophotometrically. Four mutants show a higher reaction rate with the radical as compared to the wild type. These mutants are used for the construction of superoxide sensors based on thiol-modified gold electrodes and covalently fixed proteins. We found that the E66K mutant-based electrode has a clearly higher sensitivity in comparison with the wild-type-based sensor while retaining the high selectivity and showing a good storage stability.
Year:
2009
Publication type:
Journal article
Journal:
Analytical Chemistry
ISSN:
0003-2700
Number:
8
Volume:
81
Pages:
2976-2984
Language:
English
Document status:
Published
PubListerURL:
https://publister.bib.th-wildau.de/publister/public/publication/254
Wegerich, F., Turano, P., Allegrozzi, M., Möhwald, H., & Lisdat, F. (2009). Cytochrome c Mutants for Superoxide Biosensors Analytical Chemistry. 81 (8), 2976-2984.
@article{254,
author = {Wegerich, Franziska and Turano, Paola and Allegrozzi, Marco and Möhwald, Helmuth and Lisdat, Fred},
title = {Cytochrome c Mutants for Superoxide Biosensors},
journal = {Analytical Chemistry},
year = {2009},
volume = {81},
number = {8},
pages = {2976-2984},
doi = {10.1021/ac802571h},
}