Cloning and characterization of an extracellular serine protease from the nematode-trapping fungus Arthrobotrys conoides
Cloning and characterization of an extracellular serine protease from the nematode-trapping fungus Arthrobotrys conoides
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DOI：
10.1007/s00203-007-0233-x
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发表时间：
2007-03
影响因子：
2.8
通讯作者：
Jinkui Yang;Juan Li;L. Liang;B. Tian;Ying Zhang;Chun-mei Cheng;Ke-Qin Zhang
中科院分区：
文献类型：
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作者：
Jinkui Yang;Juan Li;L. Liang;B. Tian;Ying Zhang;Chun-mei Cheng;Ke-Qin Zhang
从捕食线虫的真菌Arthroboboacumconoides中纯化了一种分子量为35 kDa的胞外丝氨酸蛋白酶（Ac1）。Ac1的最适酶活为pH7.0和53.2°C（超过20 min）。Ac1可降解多种底物，包括酪蛋白、明胶、牛血清白蛋白、胶原和线虫培养物。此外，Ac1对自由生活的线虫Panagrellus redivus和松材线虫Bursaphelenchus xylophilus也有抑制作用，表明Ac1可能参与了线虫的侵染。Ac1的编码基因包含一个60 bp的内含子和两个外显子，编码一个411个氨基酸残基的多肽。Ac1的推导的多肽序列显示出高度的相似性，两个先前报道的丝氨酸蛋白酶PII和Mlx从其他线虫捕捉真菌（81%的氨基酸序列同一性）。然而，三种蛋白酶Ac1、Aoz1和Mlx的最适温度分别为53.2、45和65°C。与PII相比，Ac1似乎对明胶、牛血清白蛋白和非变性胶原蛋白具有显着更高的活性。此外，我们的生物测定实验表明，Ac1是更有效的固定P。重新划分木生植物
An extracellular serine protease (Ac1) with a molecular mass of 35 kDa was purified from the nematode-trapping fungusArthrobotrys conoides. The optimum activity of Ac1 is at pH 7.0 and 53.2°C (over 20 min). Ac1 can degrade a broad range of substrates including casein, gelatin, bovine serum albumin, collagen, and nematode cuticles. Moreover, the enzyme can immobilize the free-living nematodePanagrellus redivivusand the pine wood nematodeBursaphelenchus xylophilus, indicating Ac1 may be involved in infection against nematodes. The encoding gene of Ac1 contains one intron of 60-bp and two exons encoding a polypeptide of 411 amino acid residues. The deduced polypeptide sequence of Ac1 showed a high degree of similarity to two previously reported serine proteases PII and Mlx from other nematode-trapping fungi (81% aa sequence identity). However, three proteases Ac1, Aoz1 and Mlx showed optimum temperatures at 53.2, 45 and 65°C, respectively. Compared to PII, Ac1 appears to have a significantly higher activity against gelatin, bovine serum albumin, and non-denatured collagen. Moreover, our bioassay experiments showed that Ac1 is more effective at immobilizingP. redivivusthanB. xylophilus.