title: Secreted proteases from dermatophytes.
abstract: Dermatophytes are highly specialized pathogenic fungi that exclusively infect the stratum corneum, nails or hair, and it is evident that secreted proteolytic activity is important for their virulence. Endo- and exoproteases-secreted by dermatophytes are similar to those of species of the genus Aspergillus. However, in contrast to Aspergillus spp., dermatophyte-secreted endoproteases are multiple and are members of two large protein families, the subtilisins (serine proteases) and the fungalysins (metalloproteases). In addition, dermatophytes excrete sulphite as a reducing agent. In the presence of sulphite, disulphide bounds of the keratin substrate are directly cleaved to cysteine and S-sulphocysteine, and reduced proteins become accessible for further digestion by various endo- and exoproteases secreted by the fungi. Sulphitolysis is likely to be an essential step in the digestion of compact keratinized tissues which precedes the action of all proteases.
authors.affiliation: Service de Dermatologie et Vénéréologie, Laboratoire de Mycologie, BT422, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland. Michel.Monod@chuv.ch
authors.forename: Michel
authors.initials: M
authors.lastname: Monod
mesh_terms: D000818:Animals; D020689:Exopeptidases / Q000378:metabolism*; D006801:Humans; D007633:Keratins / Q000378:metabolism; D045726:Metalloproteases / Q000378:metabolism*; D008864:Microsporum / Q000201:enzymology* / Q000378:metabolism / Q000472:pathogenicity; D012697:Serine Endopeptidases / Q000378:metabolism*; D013447:Sulfites / Q000378:metabolism; D014249:Trichophyton / Q000201:enzymology* / Q000378:metabolism / Q000472:pathogenicity; D014774:Virulence
chemical_list: D013447:Sulfites; D007633:Keratins; D020689:Exopeptidases; D045726:Metalloproteases; D012697:Serine Endopeptidases