Isolation of a Germin-like Protein with Manganese Superoxide Dismutase Activity from Cells of a Moss, Barbula unguiculata *
Isolation of a Germin-like Protein with Manganese Superoxide Dismutase Activity from Cells of a Moss, Barbula unguiculata *
复制标题
DOI：
10.1074/jbc.274.47.33274
复制
发表时间：
1999-11
期刊：
影响因子：
--
通讯作者：
T. Yamahara;Tadahiko Shiono;Takanori Suzuki;Katuyuki Tanaka;S. Takio;Kiichi Sato;S. Yamazaki;T. Satoh
中科院分区：
文献类型：
--
作者：
T. Yamahara;Tadahiko Shiono;Takanori Suzuki;Katuyuki Tanaka;S. Takio;Kiichi Sato;S. Yamazaki;T. Satoh
从藓类植物Barbula unguiculata中分离到一种新的细胞外锰超氧化物歧化酶（SOD）。SOD为糖蛋白；凝胶过滤色谱法估计其天然形态的表观分子质量为120 kDa，飞行时间质谱法估计其单体的表观分子质量为22,072 Da。该蛋白含锰量为0.80 Mn/单体。分离到细胞外Mn-SOD编码基因cDNA克隆。序列分析表明，该基因与几种植物的germin（草酸氧化酶）和发芽样蛋白（GLPs）具有很强的相似性，并具有germin家族成员的全部特征。因此，编码该细胞外Mn-SOD的克隆被命名为B. unguiculata GLP （BuGLP）。BuGLP不具有草酸氧化酶活性。此外，还分离到了一个编码苔藓线粒体Mn-SOD基因的cDNA。它的氨基酸序列与BuGLP几乎没有相似之处，尽管在不同生物的线粒体mn - sod中观察到非常接近的相似性。BuGLP是第一个真正被证明是具有Mn-SOD活性但没有草酸氧化酶活性的金属蛋白的发芽样蛋白。
A novel extracellular Mn-superoxide dismutase (SOD) was isolated from a moss, Barbula unguiculata. The SOD was a glycoprotein; the apparent molecular mass of its native form was 120 kDa, as estimated by gel filtration chromatography, and that of its monomer was 22,072 Da, as estimated by time of flight mass spectroscopy. The protein had manganese with a stoichiometry of 0.80 Mn/monomer. The cDNA clone for a gene encoding the extracellular Mn-SOD was isolated. Sequence analysis showed that it has a strong similarity to germin (oxalate oxidase) and germin-like proteins (GLPs) of several plant species and possesses all the characteristic features of members of the germin family. The clone encoding this extracellular Mn-SOD was therefore designated B. unguiculata GLP (BuGLP). BuGLP had no oxalate oxidase activity. In addition, the cDNA for a gene encoding the moss mitochondrial Mn-SOD was isolated. Its amino acid sequence had little similarity to that of BuGLP, even though a close similarity was observed among the mitochondrial Mn-SODs of various organisms. BuGLP was the first germin-like protein that was really demonstrated to be a metalloprotein with Mn-SOD activity but no oxalate oxidase activity.