Virulence of an aspergillopepsin-deficient mutant of Aspergillus fumigatus and evidence for another aspartic proteinase linked to the fungal cell wall

Détails

ID Serval
serval:BIB_9FDA6E45AAD9
Type
Article: article d'un périodique ou d'un magazine.
Sous-type
Etude de cas (case report): rapporte une observation et la commente brièvement.
Collection
Publications
Institution
Titre
Virulence of an aspergillopepsin-deficient mutant of Aspergillus fumigatus and evidence for another aspartic proteinase linked to the fungal cell wall
Périodique
Journal of Medical and Veterinary Mycology
Auteur⸱e⸱s
Reichard  U., Monod  M., Odds  F., Ruchel  R.
ISSN
0268-1218 (Print)
Statut éditorial
Publié
Date de publication
06/1997
Volume
35
Numéro
3
Pages
189-96
Notes
Case Reports
Journal Article --- Old month value: May-Jun
Résumé
A gene replacement was performed to produce mutants of Aspergillus fumigatus deficient in the aspergillopepsin PEP (E.C. 3.4.23.18). The correct replacement of the PEP gene was confirmed by PCR and Southern hybridization experiments, whereas the absence of PEP production was demonstrated by Western blots. The culture supernatant of the transformants showed no detectable acid proteinase activity, suggesting that there is only one acid proteinase secreted by the fungus. The wild-type strain and the PEP-deficient mutants invaded tissues to a similar extent and produced comparable mortality in guinea pigs. As PEP represents a third secretory proteinase of A. fumigatus and the other two proteinases also did not show significant influence on fungal invasiveness, it is probable that secreted proteinases do not contribute decisively to tissue invasion in the pathogenesis of systemic aspergillosis. However, immunofluorescence on A. fumigatus colonies using polyclonal antibodies to PEP showed a similar pattern for the wild-type and for the mutants, with a bright fluorescence on young conidiophores, on submerged mycelium and on the tips of growing aerial mycelium. Conidia and mature aerial hyphae were not fluorescent. This pattern could reflect the existence of another crossreacting aspartic proteinase (PEP2) which was found to be sensitive to pepstatin but tightly linked to the fungal cell wall.
Mots-clé
Animals Aspartic Endopeptidases/analysis/*genetics/metabolism Aspergillosis/*microbiology Aspergillus fumigatus/genetics/isolation & purification/*pathogenicity Cell Wall/enzymology Fluorescent Antibody Technique *Genes, Fungal Guinea Pigs Humans Male Mice Mice, Inbred Strains Middle Aged *Mutation Pepstatins/pharmacology Plasmids Polymerase Chain Reaction Protease Inhibitors/pharmacology Virulence/genetics
Pubmed
Web of science
Création de la notice
25/01/2008 16:47
Dernière modification de la notice
20/08/2019 15:06
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