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Designing an O 2 ‐Insensitive Glucose Oxidase for Improved Electrochemical Applications
Author(s) -
Tremey Emilie,
StinesChaumeil Claire,
Gounel Sébastien,
Mano Nicolas
Publication year - 2017
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201700646
Subject(s) - glucose oxidase , electrochemistry , redox , reactivity (psychology) , chemistry , electrode , kinetics , serine , diffusion , combinatorial chemistry , inorganic chemistry , biochemistry , enzyme , medicine , physics , alternative medicine , pathology , quantum mechanics , thermodynamics
The O 2 reactivity of flavoproteins and particularly, glucose oxidase, is a limitation for numerous biotechnological applications, and this has been the subject of intense research. In the present study, we performed site‐directed mutations on Val464 of GOx from Penicilium amagasakiense and combined steady‐state, rapid kinetics and electrochemistry to investigate the effect of such mutations on the O 2 reactivity. We propose that replacing the non‐polar Valine with a polar Serine permits to decrease the diffusion/stabilization of O 2 near the active redox center without altering the oxidation of glucose. When incorporated in osmium hydrogels, the resulting electrodes were insensitive to O 2 in the 0.5–60 mM glucose concentration range and were 4.7 times more stable under continuous operation than similar electrodes made with the native GOx. To the best of our knowledge, this is the first example in which O 2 sensitivity in GOx can be significantly decrease without altering the electrochemical efficiency for glucose oxidation.