Fig. 4

Recombinant production, purification and biochemical characterization of TP-Lac2. A Recombinant TP-Lac2 production in S. cerevisiae cells (CEN.PK Lac2): the laccase activity was assayed on supernatants of cultures at 25 °C, pH 4, by using ABTS as substrate. Experiments were performed in triplicate and the error bars indicate the standard deviation of the data. B Ion-exchange chromatography of culture supernatants on a DEAE-sepharose manually packed column: the laccase activity in the elution fractions (in red) was measured using the ABTS assay. The NaCl gradient is represented as a dotted line. C SDS-PAGE analysis of purified TP-Lac2. M: molecular weight marker. The effects of temperature (D) and pH (E) on the activity of TP-Lac2 were determined using ABTS as substrate (final concentration: 1 mM). Experiments were performed in quadruplicate and the shadowed area refers to the standard deviation of the data (n = 4). F Substrate specificity of TP-Lac2, assays were carried out using ABTS, 2,6-DMP and guaiacol in the optimal catalysis conditions at substrate concentration of 1 mM. Experiments were performed in quadruplicate and the error bars indicate the standard deviation of the data (n = 4)