title: Cloning and disruption of the antigenic catalase gene of Aspergillus fumigatus.
abstract: Aspergillus fumigatus possesses two catalases (described as fast and slow on the basis of their electrophoretic mobility). The slow catalase has been recognized as a diagnostic antigen for aspergillosis in immunocompetent patients. The antigenic catalase has been purified. The enzyme is a tetrameric protein composed of 90-kDa subunits. The corresponding cat1 gene was cloned, and sequencing data show that the cat1 gene codes for a 728-amino-acid polypeptide. A recombinant protein expressed in Pichia pastoris is enzymatically active and has biochemical and antigenic properties that are similar to those of the wild-type catalase. Molecular experiments reveal that CAT1 contains a signal peptide and a propeptide of 15 and 12 amino acid residues, respectively. cat1-disrupted mutants that were unable to produce the slow catalase were as sensitive to H2O2 and polymorphonuclear cells as the wild-type strain. In addition, there was no difference in pathogenicity between the cat1 mutant and its parental cat1+ strain in a murine model of aspergillosis.
authors.affiliation: Laboratoire des Aspergillus, Institut Pasteur, Paris, France.
authors.forename: J A
authors.initials: JA
authors.lastname: Calera
authors.forename: S
authors.initials: S
authors.lastname: Paris
authors.forename: M
authors.initials: M
authors.lastname: Monod
authors.forename: A J
authors.initials: AJ
authors.lastname: Hamilton
authors.forename: J P
authors.initials: JP
authors.lastname: Debeaupuis
authors.forename: M
authors.initials: M
authors.lastname: Diaquin
authors.forename: R
authors.initials: R
authors.lastname: López-Medrano
authors.forename: F
authors.initials: F
authors.lastname: Leal
authors.forename: J P
authors.initials: JP
authors.lastname: Latgé
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000946:Antigens, Fungal / Q000235:genetics*; D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000276:immunology; D002374:Catalase / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D003001:Cloning, Molecular; D005800:Genes, Fungal; D006861:Hydrogen Peroxide / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009504:Neutrophils / Q000276:immunology; D011817:Rabbits
chemical_list: D000946:Antigens, Fungal; D006861:Hydrogen Peroxide; D002374:Catalase