Aminopeptidases and dipeptidyl-peptidases secreted by the dermatophyte Trichophyton rubrum

Microbiology. 2005 Jan;151(Pt 1):145-155. doi: 10.1099/mic.0.27484-0.

Abstract

The nature of secreted aminopeptidases in Trichophyton rubrum was investigated by using a reverse genetic approach. T. rubrum genomic and cDNA libraries were screened with Aspergillus spp. and Saccharomyces cerevisiae aminopeptidase genes as the probes. Two leucine aminopeptidases, ruLap1 and ruLap2, and two dipeptidyl-peptidases, ruDppIV and ruDppV, were characterized and compared to orthologues secreted by Aspergillus fumigatus using a recombinant protein from Pichia pastoris. RuLap1 is a 33 kDa nonglycosylated protein, while ruLap2 is a 58-65 kDa glycoprotein. The hydrolytic activity of ruLap1, ruLap2 and A. fumigatus orthologues showed various preferences for different aminoacyl-7-amido-4-methylcoumarin substrates, and various sensitivities to inhibitors and cations. ruDppIV and ruDppV showed similar activities to A. fumigatus orthologues. In addition to endopeptidases, the four aminopeptidases ruLap1, ruLap2, ruDppIV and ruDppV were produced by T. rubrum in a medium containing keratin as the sole nitrogen source. Synergism between endo- and exopeptidases is likely to be essential for dermatophyte virulence, since these fungi grow only in keratinized tissues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aspergillus fumigatus / enzymology
  • Aspergillus fumigatus / genetics
  • Cloning, Molecular
  • Culture Media
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / genetics
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / metabolism*
  • Humans
  • Keratins / metabolism
  • Leucyl Aminopeptidase / genetics
  • Leucyl Aminopeptidase / metabolism*
  • Molecular Sequence Data
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics
  • Substrate Specificity
  • Trichophyton / enzymology*
  • Trichophyton / genetics
  • Trichophyton / growth & development

Substances

  • Culture Media
  • Recombinant Proteins
  • Keratins
  • Leucyl Aminopeptidase
  • Dipeptidyl-Peptidases and Tripeptidyl-Peptidases

Associated data

  • GENBANK/AF407232
  • GENBANK/AY436356
  • GENBANK/AY436357
  • GENBANK/AY496929
  • GENBANK/AY496930
  • GENBANK/AY497021
  • GENBANK/L48074
  • GENBANK/U87950