Distribution of chymoelastases and trypsin-like enzymes in five species of entomopathogenic deuteromycetes.
Distribution of chymoelastases and trypsin-like enzymes in five species of entomopathogenic deuteromycetes.
复制标题
DOI：
10.1016/0003-9861(87)90329-8
复制
发表时间：
1987-10
影响因子：
3.9
通讯作者：
R. S. St. Leger;R. Cooper;A. Charnley
中科院分区：
文献类型：
--
作者：
R. S. St. Leger;R. Cooper;A. Charnley
9株昆虫致病后菌——绿僵菌、球孢白僵菌、莱氏竖菌、野菌和阿氏菌——产生的碱性（pI bbb7.0）凝弹性酶具有扩展的结合位点，包括至少4或5个亚位点，主要结合位点上的疏水残基优先。大多数分离物还产生额外的酸性酶，对酯和酰胺底物具有相似的特异性，但缺乏对弹性蛋白的活性。酸性酶和碱性酶都能降解高蛋白天青或刺槐角质层，抑制研究表明，活性位点具有必需丝氨酸和组氨酸残基。尽管催化性质相似，产生的抗metarhiziumchymoelastase的抗体仅与四种metarhizium菌株中的两种酶交叉反应；其他菌株的酶均未发生交叉反应。两株绿僵菌产生第三类蛋白酶，可降解Bz-AA-AA-Arg-NA底物（AA，各种氨基酸）和隐藏蛋白。类似的肽酶由其他分离物产生，但它们对bz - ph - val - arg - na具有特异性，对胰蛋白酶抑制剂的敏感性较低。讨论了在五属昆虫病原体中存在不同但相似的蛋白酶形式对病理学的可能意义。
Nine isolates of the entomopathogenic deuteromycetesMetarhizium anisopliae, Beauveria bassiana, Vertidllium lecanii, Nomuraea rileyi, andAschersonia aleyrodisproduced basic (pI > 7.0) chymoelastases that possessed extended binding sites, comprising at least four or five subsites, with preference for hydrophobic residues at the primary binding site. Most isolates also produced additional acidic enzymes with similar specificities against ester and amide substrates but which lacked activity against elastin. Both acidic and basic enzymes degraded high protein azure or locust cuticle and, as shown by inhibition studies, possessed essential serine and histidine residues in the active site. In spite of similarities in catalytic properties antibodies generated against aMetarhiziumchymoelastase cross-reacted only with enzymes from two (out of four)Metarhiziumisolates; enzymes from all other isolates did not cross-react. Two isolates ofMetarhiziumproduced a third class of protease which degraded Bz-AA-AA-Arg-NA substrates (AA, various amino acids) and hide protein azure. Analogous peptidases were produced by other isolates but they were specific for Bz-Phe-Val-Arg-NA and showed less sensitivity to trypsin inhibitors. The possible significance to pathology of the presence of diverse yet similar protease forms in five genera of entomopathogens is discussed.