Segers R, Butt T M, Keen J N, Kerry B R, Peberdy J F
Entomology and Nematology Department, IACR-Rothamsted Experimental Station, Harpenden, Herts, UK.
FEMS Microbiol Lett. 1995 Mar 1;126(3):227-31. doi: 10.1111/j.1574-6968.1995.tb07423.x.
The major extracellular proteases from the nematophagous fungus Verticillium chlamydosporium and the entomophagous fungus Metarhizium anisopliae, VCP1 and Pr1, respectively, are closely related both functionally and serologically. Antibodies raised against either enzyme cross-reacted with both antigens, suggesting that they have common epitopes. The VCP1 and Pr1 antisera labelled bovine pancreatic elastase and proteinase K, respectively. Neither antiserum reacted with commercial chymotrypsin. An antiserum to a serine protease from the closely related V. suchlasporium also cross-reacted with VCP1 and Pr1. In contrast, a polyclonal antibody to an isoform of Pr1 exclusive to M. anisopliae isolate ME1 failed to recognize Pr1 from M. anisopliae V245 or VCP1. The N-terminal amino acid sequence of VCP1 revealed similarities with subtilisin-like enzymes from other fungi, but the closest match was with Pr1. The pure enzymes, VCP1 and Pr1, failed to hydrolyse mono-aminoacyl-naphthylamide substrates but demonstrated dipeptidyl peptidase activity against Gly-Pro-beta NA and Leu-Ala-beta NA, respectively. These results are discussed in the context of specificity of invertebrate mycopathogens.
来自食线虫真菌厚垣轮枝菌和食虫真菌绿僵菌的主要细胞外蛋白酶，分别为VCP1和Pr1，在功能和血清学上密切相关。针对这两种酶产生的抗体与两种抗原均发生交叉反应，表明它们具有共同的表位。VCP1抗血清和Pr1抗血清分别标记牛胰弹性蛋白酶和蛋白酶K。两种抗血清均不与市售的胰凝乳蛋白酶发生反应。来自密切相关的拟青霉的一种丝氨酸蛋白酶的抗血清也与VCP1和Pr1发生交叉反应。相反，针对绿僵菌菌株ME1特有的Pr1同工型的多克隆抗体无法识别绿僵菌V245的Pr1或VCP1。VCP1的N端氨基酸序列显示出与其他真菌的枯草杆菌蛋白酶样酶有相似性，但最接近的匹配是与Pr1。纯化的酶VCP1和Pr1不能水解单氨基酰萘酰胺底物，但分别对甘氨酰-脯氨酰-β-萘胺和亮氨酰-丙氨酰-β-萘胺表现出二肽基肽酶活性。将结合无脊椎动物致病真菌的特异性来讨论这些结果。
