title: The subtilisins of the invertebrate mycopathogens Verticillium chlamydosporium and Metarhizium anisopliae are serologically and functionally related.
abstract: 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.
authors.affiliation: Entomology and Nematology Department, IACR-Rothamsted Experimental Station, Harpenden, Herts, UK.
authors.forename: R
authors.initials: R
authors.lastname: Segers
authors.forename: T M
authors.initials: TM
authors.lastname: Butt
authors.forename: J N
authors.initials: JN
authors.lastname: Keen
authors.forename: B R
authors.initials: BR
authors.lastname: Kerry
authors.forename: J F
authors.initials: JF
authors.lastname: Peberdy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000908:Antibodies, Fungal / Q000276:immunology; D005656:Fungal Proteins / Q000737:chemistry* / Q000276:immunology; D007313:Insecta / Q000469:parasitology; D003904:Mitosporic Fungi / Q000201:enzymology* / Q000276:immunology; D008969:Molecular Sequence Data; D009348:Nematoda / Q000469:parasitology; D010455:Peptides / Q000378:metabolism; D010802:Phylogeny; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000276:immunology; D013045:Species Specificity; D013379:Substrate Specificity; D013381:Subtilisins / Q000737:chemistry* / Q000276:immunology / Q000502:physiology
chemical_list: D000908:Antibodies, Fungal; D005656:Fungal Proteins; D010455:Peptides; D012697:Serine Endopeptidases; D013381:Subtilisins; C093194:VCP1 protein, Verticillium chlamydosporium; C093192:pr1 protein, Metarhizium anisopliae