THE NEMATOPHAGOUS FUNGUS VERTICILLIUM-CHLAMYDOSPORIUM PRODUCES A CHYMOELASTASE-LIKE PROTEASE WHICH HYDROLYZES HOST NEMATODE PROTEINS IN-SITU
THE NEMATOPHAGOUS FUNGUS VERTICILLIUM-CHLAMYDOSPORIUM PRODUCES A CHYMOELASTASE-LIKE PROTEASE WHICH HYDROLYZES HOST NEMATODE PROTEINS IN-SITU
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DOI：
10.1099/00221287-140-10-2715
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发表时间：
1994-10-01
期刊：
影响因子：
2.8
通讯作者：
PEBERDY, JF
中科院分区：
文献类型：
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作者：
SEGERS, R;BUTT, TM;PEBERDY, JF
食线虫真菌厚孢轮枝菌（Verticillium chlamydosporium）在以大豆蛋白胨为唯一碳源和氮源的液体培养中分泌多种蛋白酶。一种蛋白酶，VCP 1（M（r）33000，pI 10.2），在游离溶液中使用制备性等电聚焦从培养物中纯化14倍至表观均一性，并且显示出快速水解胰凝乳蛋白酶底物Suc-（Ala）（2）-Pro-Phe-pNA和弹性蛋白。VCP 1对Suc-（Ala）（2）-Pro-Phe-pNA的Km为4.3 x 10（-5）M，k（cat）为5.8 s（-1）。对PMSF和TPCK高度敏感，对鸡蛋清和大豆胰蛋白酶抑制剂中度敏感。VCP 1降解了广泛的聚合物底物，包括Azocoll，皮蛋白，弹性蛋白，酪蛋白和白蛋白，并占了大部分的非特异性蛋白酶活性检测培养瓶。纯化的酶原位水解寄主南方根结线虫卵壳外层的蛋白质并暴露其几丁质层。VCP 1是由几个分离的厚垣孢子轮枝菌和蜡蚧轮枝菌分泌的，它们分别是线虫和昆虫的病原菌，而不是植物病原性的轮枝菌。这些观察结果表明，VCP 1或类似的酶可能在无脊椎动物的感染中发挥作用。
The nematophagous fungus Verticillium chlamydosporium secreted several proteases in submerged culture in which soya peptone was the sole carbon and nitrogen source. One protease, VCP1 (M(r) 33000, pI 10.2), was purified 14-fold from culture filtrates to apparent homogeneity using preparative isoelectric focusing in free solution, and shown to rapidly hydrolyse the chymotrypsin substrate Suc-(Ala)(2)-Pro-Phe-pNA and elastin. VCP1 had a K-m for Suc-(Ala)(2)-Pro-Phe-pNA of 4.3 x 10(-5) M and a k(cat) of 5.8 s(-1). It was highly sensitive to PMSF and TPCK, but only moderately sensitive to chicken egg-white and soya bean trypsin inhibitors. VCP1 degraded a wide range of polymeric substrates, including Azocoll, hide protein, elastin, casein and albumin, and accounted for most of the non-specific protease activity detected in culture filtrates. The purified enzyme hydrolysed proteins in situ from the outer layer of the egg shell of the host nematode Meloidogyne incognita and exposed its chitin layer. VCP1 was secreted by several isolates of V. chlamydosporium and V. lecanii, pathogens of nematodes and insects respectively, but not plant-pathogenic species of Verticillium. These observations suggest that VCP1 or similar enzyme(s) may play a role in the infection of invertebrates.