Purification, Characterization, and Molecular Cloning of a Pyranose Oxidase from the Fruit Body of the Basidiomycete,<i>Tricholoma matsutake</i>
作者:Yoshimitsu TAKAKURA、Shigeru KUWATA
DOI:10.1271/bbb.67.2598
日期:2003.1
A new H2O2-generating pyranose oxidase was purified as a strong antifungal protein from an arbuscular mycorrhizal fungus, Tricholoma matsutake. The protein showed a molecular mass of 250 kDa in gel filtration, and probably consisted of four identical 62 kDa subunits. The protein contained flavin moiety and it oxidized D-glucose at position C-2. H2O2 and D-glucosone produced by the pyranose oxidase reaction showed antifungal activity, suggesting these compounds were the molecular basis of the antifungal property. The Vmax, Km, and kcat for D-glucose were calculated to be 26.6 U/mg protein, 1.28 mM, and 111/s, respectively. The enzyme was optimally active at pH 7.5 to 8.0 and at 50°C. The preferred substrate was D-glucose, but 1,5-anhydro-D-glucitol, L-sorbose, and D-xylose were also oxidized at a moderate level. The cDNA encodes a protein consisting of 564 amino acids, showing 35.1% identity to Coriolus versicolor pyranose oxidase. The recombinant protein was used for raising the antibody.
从一种内生菌根真菌松口蘑中纯化得到一种新的H2O2生成吡喃糖氧化酶,该酶具有强烈的抗真菌蛋白活性。该蛋白在凝胶过滤中表现出250 kDa的分子质量,可能由四个相同的62 kDa亚基组成。该蛋白含有黄素部分,并在C-2位置氧化D-葡萄糖。由吡喃糖氧化酶反应产生的H2O2和D-葡糖酮具有抗真菌活性,表明这些化合物是其抗真菌特性的分子基础。D-葡萄糖的Vmax、Km和kcat分别为26.6 U/mg蛋白、1.28 mM和111/s。该酶在pH 7.5至8.0和50°C下活性最佳。其首选底物是D-葡萄糖,但1,5-脱水-D-山梨醇、L-山梨糖和D-木糖也能在中等程度上被氧化。该cDNA编码一个由564个氨基酸组成的蛋白质,与杂色革盖菌的吡喃糖氧化酶有35.1%的同源性。使用重组蛋白制备抗体。