22056522

not annotated - annotated - LINNAEUS only

A heme peroxidase of the ascomyceteous lichen Leptogium saturninum oxidizes high-redox potential substrates.

Lichens belonging to the order Peltigerales display strong activity of multi-copper oxidases (e.g. tyrosinase) as well as heme-containing peroxidases. The lichen peroxidase was purified to homogeneity from the thallus of Leptogium saturninum (LsaPOX) by fast protein liquid chromatography and then partially characterized. The oligomeric protein occurs as both 79kDa dimeric and 42kDa monomeric forms, and displayed broad substrate specificity. In addition to an ability to oxidize classic peroxidase substrates (e.g. 2,6-dimethoxyphenol), the enzyme could convert recalcitrant compounds such as synthetic dyes (e.g. Azure B and Reactive Blue 5), 4-nitrophenol and non-phenolic methoxylated aromatics (e.g. veratryl alcohol). Comparing LsaPOX with a basidiomycete dye-decolorizing (DyP)-type peroxidase from Auricularia auricula-judae showed that the lichen enzyme has a high-redox potential, with oxidation capabilities ranging between those of known plant and fungal peroxidases. Internal peptide fragments show homology (up to 60%) with putative proteins from free-living ascomycetes (e.g. Penicillium marneffei and Neosartorya fischeri), but not to sequences of algal or cyanobacterial peptides or to known fungal, bacterial or plant peroxidases. LsaPOX is the first heme peroxidase purified from an ascomyceteous lichen that may help the organism to successfully exploit the extreme micro-environments in which they often grow.



Ann file

T1	Species 46 66	Leptogium saturninum

N1 Reference T1 Taxonomy:243206

T2 Species 332 352 Leptogium saturninum

N2 Reference T2 Taxonomy:243206

T3 Species 919 945 Auricularia auricula-judae

N3 Reference T3 Taxonomy:29892

T4 Species 1204 1225 Penicillium marneffei

N4 Reference T4 Taxonomy:37727

T5 Species 1230 1250 Neosartorya fischeri

N5 Reference T5 Taxonomy:36630