A novel oxygenase from Pleurotus sapidus transforms valencene to nootkatone

A selective and highly efficient allylic oxidation of the sesquiterpene (+)-valencene to (+)-nootkatone was achieved with lyophilisate of the basidiomycete Pleurotus sapidus. The responsible enzymatic activity was biochemically characterised and purified by chromatographic and electrophoretic methods. Peptide sequences obtained by mass spectrometry showed homologies to oxygenases from various ascomycetes. Based on the peptide sequences, the encoding cDNA was amplified from a cDNA library of P. sapidus by PCR. The cloned sequence consisted of 1309 bp with an open reading frame of 1191 bp. Based on database research, the translated amino acid sequence of 396 amino acids showed on the protein level homologies of ∼50% to putative lipoxygenases from Aspergillus fumigatus and Laccaria bicolor as well as 26% homology to the sequence of lipoxygenase-1 from soy bean (Glycine max). A lipoxygenase from a basidiomycetous fungus has not yet been characterised on a molecular level.