Laccase mutants

A method of constructing a variant of a parent Coprinus-like laccase having laccase activity and having one or more of the following alterations:

• a. altered oxidation potential
• b. altered pH optimum
• c. altered mediator efficiency
• d. altered O2/OH−-pathway
• as compared to said parent Coprinus-like laccase,
• said method comprising:
• I) modeling the parent Coprinus-like laccase on the three-dimensional amino acid structure of Coprinus cinereus laccase, as defined by the atomic coordinates in Table 1, to produce a three-dimensional modeled structure of the parent Coprinus-like laccase,
• ii) identifying, in the three-dimensional modeled structure obtained in step (I), a structural part of the parent Coprinus-like laccase which is predicted to be responsible for differences in oxidation potential, pH optimum, mediator efficiency, or O2/OH−-pathway between the parent Coprinus-like laccase and the Coprinus cinereus laccase, and
• iii) modifying the part of the parent Coprinus-like laccase identified in step (ii) to produce a variant of the parent Coprinus-like laccase, said variant having laccase activity and altered oxidation potential and/or altered pH optimum and/or altered mediator efficiency and/or an altered O2/OH−-pathway as compared to said parent Coprinus-like laccase;
• wherein said parent Coprinus-like laccase has laccase enzymatic activity and has an amino acid sequence at least 50% homologous to SEQ ID NO:
• 1 when homology is measured by GAP Version 8.1, using a gap weight of 3.0 and a length weight of 0.1.