Designer laccases: a vogue for high-potential fungal enzymes?

Laccases are blue multicopper oxidases that catalyse the four-electron reduction of O2 to water coupled with the oxidation of small organic substrates. Secreted basidiomycete white-rot fungal laccases orchestrate this with high thermodynamic efficiency, making these enzymes excellent candidates for exploitation as industrial oxidants. However, these fungi are less tractable genetically than the ascomycetes, which predominantly produce lower-potential laccases. We address the state-of-play regarding expression of high reduction potential laccases in heterologous hosts, and issues regarding enzyme glycosylation status. We describe the synergistic role of structural biology, particularly in unmasking structure–function relationships following genetic modification and their collective impact on laccase yields. Such recent research draws closer the prospect of industrial quantities of designer, fit-for-purpose laccases.