Gillespie JP, Bateman R, Charnley AK
School of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom.
J Invertebr Pathol. 1998 Mar;71(2):128-37. doi: 10.1006/jipa.1997.4733.
The production of the subtilisin proteinase, PR1, and the trypsin-like enzyme, PR2, in liquid cultures of 19 isolates of Metarhizium spp. was investigated. PR1 activity was generally observed 72 h after inoculation whilst PR2 activity was detected in most strains 48 h after inoculation. PR1 was partially purified from each isolate of Metarhizium spp. The ability of this enzyme from each isolate to degrade different types of insect cuticle was investigated. The cuticle types used were Manduca sexta pupal cuticle, adult desert locust (Schistocerca gregaria) wing cuticle, abdominal cuticle, and pharate adult locust abdominal cuticle. These cuticle types differ in their protein composition and degree of sclerotization. PR1 hydrolyzed the locust cuticle to different degrees. The data suggest a hierarchy for the susceptibility to hydrolysis in the order pharate adult abdominal > adult abdominal > wing. There was no significant correlation between the ability of the enzymes to degrade any of the cuticle types and median lethal time of the isolates against the desert locust. However, a correlation was found between the ability of enzymes to hydrolyze different locust cuticles. Such correlations were not apparent to the same extent between M. sexta cuticle and the locust cuticles. These results are discussed in terms of a possible contribution of PR1 to host specificity. Copyright 1998 Academic Press.
对19株绿僵菌在液体培养物中枯草杆菌蛋白酶PR1和类胰蛋白酶PR2的产生情况进行了研究。接种后72小时普遍观察到PR1活性，而大多数菌株在接种后48小时检测到PR2活性。从绿僵菌的每一个分离株中对PR1进行了部分纯化。研究了来自每个分离株的这种酶降解不同类型昆虫表皮的能力。所使用的表皮类型有烟草天蛾蛹表皮、成年沙漠蝗（沙漠飞蝗）翅表皮、腹部表皮以及蝗蝻腹部表皮。这些表皮类型在蛋白质组成和硬化程度上有所不同。PR1对蝗虫表皮有不同程度的水解作用。数据表明对水解的敏感性顺序为蝗蝻腹部＞成年腹部＞翅。酶降解任何一种表皮类型的能力与分离株对沙漠蝗的半数致死时间之间没有显著相关性。然而，发现酶水解不同蝗虫表皮的能力之间存在相关性。在烟草天蛾表皮和蝗虫表皮之间，这种相关性在相同程度上并不明显。就PR1对宿主特异性的可能作用对这些结果进行了讨论。版权所有1998年学术出版社。
