Unit of Environmental Biotechnology, International Graduate School of Zittau, Markt 23, 02763 Zittau, Germany.
Fungal Genet Biol. 2011 Dec;48(12):1139-45. doi: 10.1016/j.fgb.2011.10.004. Epub 2011 Oct 28.
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 79 kDa dimeric and 42 kDa 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.
地衣中的 Peltigerales 目生物具有较强的多铜氧化酶（如酪氨酸酶）和含血红素的过氧化物酶活性。地衣过氧化物酶从黄裙竹荪（LsaPOX）的叶状体中通过快速蛋白质液相色谱法被纯化至均一性，然后对其进行部分特性描述。该寡聚蛋白既以 79 kDa 二聚体形式又以 42 kDa 单体形式存在，且显示出广泛的底物特异性。除了能够氧化经典过氧化物酶底物（例如 2,6-二甲氧基苯酚）之外，该酶还可以转化难处理的化合物，例如合成染料（例如 Azure B 和 Reactive Blue 5）、4-硝基苯酚和非酚类甲氧基芳烃（例如藜芦醇）。将 LsaPOX 与来自黑木耳（Auricularia auricula-judae）的担子菌染料脱色（DyP）型过氧化物酶进行比较表明，地衣酶具有较高的氧化还原电位，其氧化能力介于已知的植物和真菌过氧化物酶之间。内部肽片段与来自自由生活的子囊菌（例如马尔尼菲青霉和谢氏内孢霉）的假定蛋白质具有同源性（高达 60％），但与藻类或蓝细菌肽序列或已知的真菌、细菌或植物过氧化物酶没有同源性。LsaPOX 是从子囊菌地衣中纯化出来的第一个血红素过氧化物酶，可能有助于该生物成功利用其生长的极端微环境。
