Peroxidase Activity of Myoglobin Variants Reconstituted with Artificial Cofactors

Autor: Chao Guo, Robert J. Chadwick, Adam Foulis, Giada Bedendi, Andriy Lubskyy, Kyle J. Rodriguez, Michela M. Pellizzoni, Ross D. Milton, Rebecca Beveridge, Nico Bruns
Rok vydání: 2022
Předmět:
Zdroj: ChemBioChem. 23
ISSN: 1439-7633
1439-4227
DOI: 10.1002/cbic.202200197
Popis: Myoglobin (Mb) can react with hydrogen peroxide (H 2O 2) to form a highly active intermediate compound and catalyse oxidation reactions. To enhance this activity, known as pseudo-peroxidase activity, previous studies have focused on the modification of key amino acid residues of Mb or the heme cofactor. In this work, the Mb scaffold (apo-Mb) was systematically reconstituted with a set of cofactors based on six metal ions and two ligands. These Mb variants were fully characterised by UV-Vis spectroscopy, circular dichroism (CD) spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS) and native mass spectrometry (nMS). The steady-state kinetics of guaiacol oxidation and 2,4,6-trichlorophenol (TCP) dehalogenation catalysed by Mb variants were determined. Mb variants with iron chlorin e6 (Fe−Ce6) and manganese chlorin e6 (Mn−Ce6) cofactors were found to have improved catalytic efficiency for both guaiacol and TCP substrates in comparison with wild-type Mb, i. e. Fe-protoporphyrin IX-Mb. Furthermore, the selected cofactors were incorporated into the scaffold of a Mb mutant, swMb H64D. Enhanced peroxidase activity for both substrates were found via the reconstitution of Fe−Ce6 into the mutant scaffold.
Databáze: OpenAIRE
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