Kinetics of direct and substrate-mediated electron transfer of versatile peroxi...

• Author(s): Munteanu, Florentina-Daniela ; Ruiz-Duenas, Francisco J. ; T. Martinez, Angel ; Paulo, Artur Cavaco
• Date: 2005
• Persistent ID: http://hdl.handle.net/1822/2868
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Bioelectrocatalysis; Versatile peroxidase; Graphite electrode; Heterogeneous electron transfer
• Document Type: Article
• Language: English

Description

Electron transfer (ET) of versatile peroxidase (VP) was studied in the bioelectrocatalytic reduction reaction of H2O2 at peroxidase- modified graphite electrodes to obtain additional information on the kinetic characteristics of this novel ligninolytic peroxidase. Rotating disk electrodes (RDE) experiments were performed at 0 V (vs. SCE) in two different buffers (tartrate buffer, pH 5.0; and citrate buffer, pH 3.0). From measurements of the mediated and mediatorless currents of H2O2 reduction at the RDE, the percentage of VP molecules involved in direct ET (≈55%) was calculated. The peroxidase-modified electrodes were used for determination of the donor substrates in RDE mode, and the results were interpreted in terms of catalytic efficiencies.