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Published January 17, 2013 | Accepted Version + Published + Supplemental Material
Journal Article Open

Catalysis of Dioxygen Reduction by Thermus thermophilus Strain HB27 Laccase on Ketjen Black Electrodes


We present electrochemical analyses of the catalysis of dioxygen reduction by Thermus thermophilus strain HB27 laccase on ketjen black substrates. Our cathodes reliably produce 0.56 mA cm^(-2) at 0.0 V vs Ag|AgCl reference at 30 °C in air-saturated buffer, under conditions of nonlimiting O_(2) flux. We report the electrochemical activity of this laccase as a function of temperature, pH, time, and the efficiency of its conversion of dioxygen to water. We have measured the surface concentration of electrochemically active species, permitting the extraction of electron transfer rates at the enzyme-electrode interface: 1 s^(-1) for this process at zero driving force at 30 °C and a limiting rate of 23 s^(-1) at 240 mV overpotential at 50 °C.

Additional Information

© 2012 American Chemical Society. Received: October 2, 2012; Revised: November 7, 2012; Published: November 19, 2012. We thank James Mckone, Alec Durrell, and Bryan Stubbert for helpful discussions regarding electrochemistry and Kyle Lancaster for discussions regarding biochemistry. This research was funded by GCEP (Stanford), CSER (The Gordon and Betty Moore Foundation), and NIH (DK019038). Additional support was provided by a partial fellowship from the Institute for Collaborative Biotechnologies through grant W911NF-09- 0001 from the U.S. Army Research Office and the Department of Energy, Basic Energy Sciences (DE-FG03-01ER46175)(JRH PI).

Attached Files

Published - Agbo,_Heath,_Gray_2013_Catalysis_of_Dioxygen_Reduction_by_Thermus_thermophilus_Strain_HB27_Laccase_on_Ketjen_Black_Electrodes.pdf

Accepted Version - nihms423417.pdf

Supplemental Material - jp309759g_si_001.pdf



Additional details

August 19, 2023
October 23, 2023