Oxygen electroreduction by fungal laccases - combination of electrochemical and spectral data

Sergey Shleev 1,2Andreas Christenson 1Alexander I. Yaropolov 2Tautgirdas Ruzgas 1Lo Gorton 1

1. Lund University, Department of Analytical Chemistry, Lund SE-221 00, Sweden
2. Institute of Biochemistry Russian Academy of Sciences, Leninsky prospekt 33, Moscow 119071, Russian Federation


In order to investigate the mechanism of oxygen electroreduction by fungal laccase combined as well as stand alone spectral and electrochemical approaches have been exploited. Several homogeneous preparations of laccases from different basidiomycetes have been used, which were recently biochemically characterized in detail [1]. Currently it is believed that the redox potentials of the T2 and T3 copper sites in laccase are very close to each other. These potentials are approximately equal to 400 mV in low redox potential laccases and to about 800 mV in high potential laccases [2]. For the first time we report [3] that the redox potential of the T2 copper site of a high redox potential laccase from the basidiomycete Trametes hirsuta is close to 400 mV vs. NHE. Electrochemical studies of laccases from different sources show that these enzymes establish different heterogeneous ET pathways on carbon and gold electrodes [3-5]. It is determined that in the case of carbon electrodes a "normal" ET pathway can be observed, i.e., electron donor (electrode or substrate) - T1 site - T2/T3 cluster [4,5]. Due to this reason laccases adsorbed on carbon electrodes usually show well-pronounced electrocatalytic reduction of oxygen [4,5]. However, in the case of gold electrodes the heterogeneous ET pathway from the electrode to the copper centres in the enzyme globule is different [3,5]. We found that Trametes hirsuta laccase on gold electrodes electronically communicate with the electrode surface through the T2/T3 cluster. We observed that the electrons from the electrode to the T1 copper flow through the T2/T3 coppers. We confirm that T1 site has a redox potential of 780 mV [1,3,5], however, the redox potential of one copper ion from the T2/T3 cluster is close to 400 mV [3,5]. From the data about direct ET reactions of laccase on carbon and gold electrodes, as well as from the spectral results a possible modification of the catalytic cycle [6] of the enzyme is suggested and will be discussed.

[1] S. Shleev et al., Biochimie, 86 (2004) 693.
[2] B. Reinhammar, Biochim. Biophys. Acta, 275 (1972) 245.
[3] S. Shleev et al., Biochem. J., 385 (2005) 745.
[4] S. Shleev et al., Bioelectrochem., 67 (2005) 115.
[5] S. Shleev et al., Biosens. Bioelectron., 20 (2005) 2517.
[6] E. Solomon et al., Chem. Rev., 96 (1996) 2563.

Acknowledgement: This work was financially supported by the European Commission (ICA2-CT-2000-10050) and the Swedish Research Council. The Swedish Institute (SI) is acknowledged for the support of a postdoctoral fellowship for Sergey Shleev.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/4820 must be provided.


Related papers
  1. Effect of deglycosylation of cellobiose dehydrogenase applied to 3rd generation biosensors and biofuel cells
  2. Deglycosylation of glucose oxidase by PNGase F
  3. Potentially implantable bioelectronic devices for biosensing and biofuel cell applications
  4. Influence of metal cations on the turnover rate of cellobiose dehydrogenase
  5. Electron transfer studies with different sugar oxidizing enzymes and osmium polymers to improve the current density
  6. Gold nanoparticle-modified enzyme-based sugar and oxygen sensitive electrodes for biosensing and biofuel cell applications
  7. Electrochemical communication between viable bacterial cells and flexible redox polymers
  8. Direct electrochemistry of cellobiose dehydrogenase for applications in the third-generation biosensor and biofuel cell
  9. Electrochemical Communication between Viable Bacterial Cells and Flexible Redox Polymers
  10. Biosensing Applications Of Engineered Pyranose 2-oxidases Wired With Osmium Polymers
  11. Laccase-redoxpolymer cathodes for biofuel cells. Evaluation using an electrochemical robotic system.
  12. Enzymatic fuel cells
  13. Anode and cathode reactions for biofuel cells based on direct electron transfer reactions between biological components and electrodes
  14. Increasing Biosensor Sensitivity by Length Fractionated Single Walled Carbon Nanotubes
  15. Electrical Wiring of Living Bacillus subtilis Cells Using Flexible Osmium-Redox Polymers
  16. Some electrochemical properties of laccase immobilised on the Au, IrOx, or C60-Pd polymer electrode supports
  17. Amperometric determination of formaldehyde by the use of the yeast Hansenula polymorpha as a bioselective element
  18. Amperometric determinations of reducing enzyme activities in living whole S. cerevisiae cells immobilized on micro-band electrodes
  19. Wiring of whole living bacteria with osmium-redox polymers
  20. The electrochemistry of a his-tagged microperoxidase assembled onto gold electrodes
  21. Electron Transfer in Complex Two-cofactor-containing Enzymes at Alkanethiol-modified Gold Electrodes

Presentation: Short communication at SMCBS'2005 Workshop, by Sergey Shleev
See On-line Journal of SMCBS'2005 Workshop

Submitted: 2005-08-25 14:31
Revised:   2009-06-07 00:44
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine