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Electrochemical Activity of Cytochrome P450 1A2: The Relevance of O 2 Control and the Natural Electron Donor
Author(s) -
Silveira Célia M.,
Rodrigues Patrícia R.,
Ghach Wissam,
Pereira Sofia A.,
Esteves Francisco,
Kranendonk Michel,
Etienne Mathieu,
Almeida M. Gabriela
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.202001255
Subject(s) - chemistry , cyp1a2 , electrochemistry , electron transport chain , pyrolytic carbon , cytochrome p450 , enzyme , electrode , biochemistry , organic chemistry , pyrolysis
The direct electrochemical response of membrane‐bound human cytochrome P450 1A2 (CYP1A2) was studied on pyrolytic graphite electrodes, while encapsulated in a sol‐gel matrix. The enzymatic reduction of O 2 was evaluated in the presence and absence of its electron donor partner, cytochrome P450 oxidoreductase (CPR). When used without CPR, CYP1A2 was shown to be highly sensitive to O 2 even in the presence of residual amounts. Under aerobic conditions (air‐saturated solutions), the catalytic signal attributed to the reaction with O 2 was lost, suggesting the enzyme was inactivated. In contrast, the CYP1A2/CPR complex retained O 2 reductase activity with high O 2 concentration in solution. The results demonstrated a crucial role of CPR in stabilizing the immobilized CYP1A2 enzyme and in the preservation of O 2 electrocatalysis, when using this electrochemical set‐up. Though the enzyme's monooxygenase activity towards caffeine was not detected, this study highlights the complexity of coupling CYP1A2 reduction currents with substrate turnover, owing to the simultaneous electrochemical measurement of the O 2 reduction reaction.