Electrocatalysis of a Europium-Dependent Bacterial Methanol Dehydrogenase with Its Physiological Electron-Acceptor Cytochromeâ
cGJ.
Chemistry
; 25(37): 8760-8768, 2019 Jul 02.
Article
em En
| MEDLINE
| ID: mdl-30908783
ABSTRACT
We report the first electrochemical study of a lanthanoid-dependent methanol dehydrogenase (Eu-MDH) from the acidophilic verrucomicrobial methanotroph Methylacidiphilum fumariolicum SolV with its own physiological cytochromeâ
cGJ electron acceptor. Eu-MDH harbours a redox active 2,7,9-tricarboxypyrroloquinoline quinone (PQQ) cofactor which is non-covalently bound but coordinates trivalent lanthanoid elements including Eu3+ . Eu-MDH and the cytochrome were co-adsorbed with the biopolymer chitosan and cast onto a mercaptoundecanol (MU) monolayer modified Au working electrode. Cyclic voltammetry of cytochrome cGJ reveals a well-defined quasi-reversible FeIII/II redox couple at +255â
mV vs. NHE at pHâ
7.5 and this response is pH independent. The reversible one-electron response of the cytochrome cGJ transforms into a sigmoidal catalytic wave in the presence of Eu-MDH and its substrates (methanol or formaldehyde). The catalytic current was pH-dependent and pHâ
7.3 was found to be optimal. Kinetic parameters (pH dependence, activation energy) obtained by electrochemistry show the same trends as those obtained from an artificial phenazine ethosulfate/dichlorophenol indophenol assay.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Citocromos c
/
Oxirredutases do Álcool
/
Európio
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article