TY - JOUR
T1 - Bioelectrocatalysis at electrodes coated with alcohol dehydrogenase, a quinohemoprotein with heme c serving as a built-in mediator
AU - Ikeda, Tokuji
AU - Kobayashi, Daisuke
AU - Matsushita, Fumio
AU - Sagara, Takamasa
AU - Niki, Katsumi
N1 - Funding Information:
This work was supportedi n part by Grants-in Aid from the Ministry of Education, Science and Culture, Japan.
PY - 1993/12/15
Y1 - 1993/12/15
N2 - Alcohol dehydrogenase (ADH), a bacterial membrane-bound protein containing pyrroloquinoline quinone (PQQ) and heme c was held by adsorption on electrodes of gold, silver, glassy carbon, or pyrolytic graphite. All the electrodes with adsorbed ADH produced anodic currents which oxidized ethanol, in which the adsorbed ADH catalysed the electrolysis of ethanol. The electrocatalysis behavior could be described by a theoretical equation for bioelectrocatalysis at an enzyme-coated electrode, and was characterized by two quantities, the Michaelis constant Km, and maximum current density Imax/A. Using electroreflectance measurements with an ADH-coated gold electrode it was revealed that electron transfer occurred between heme c of the adsorbed ADH and the electrode. On the basis of these results, the reaction mechanism of the bioelectrocatalysis is discussed and oriented adsorption of ADH is proposed with the heme c moiety being in close contact with the electrode and with the PQQ moiety, the site reacting with the substrate, facing toward the solution.
AB - Alcohol dehydrogenase (ADH), a bacterial membrane-bound protein containing pyrroloquinoline quinone (PQQ) and heme c was held by adsorption on electrodes of gold, silver, glassy carbon, or pyrolytic graphite. All the electrodes with adsorbed ADH produced anodic currents which oxidized ethanol, in which the adsorbed ADH catalysed the electrolysis of ethanol. The electrocatalysis behavior could be described by a theoretical equation for bioelectrocatalysis at an enzyme-coated electrode, and was characterized by two quantities, the Michaelis constant Km, and maximum current density Imax/A. Using electroreflectance measurements with an ADH-coated gold electrode it was revealed that electron transfer occurred between heme c of the adsorbed ADH and the electrode. On the basis of these results, the reaction mechanism of the bioelectrocatalysis is discussed and oriented adsorption of ADH is proposed with the heme c moiety being in close contact with the electrode and with the PQQ moiety, the site reacting with the substrate, facing toward the solution.
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U2 - 10.1016/0022-0728(93)87058-4
DO - 10.1016/0022-0728(93)87058-4
M3 - Article
AN - SCOPUS:0000933312
SN - 0022-0728
VL - 361
SP - 221
EP - 228
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
IS - 1-2
ER -