Calera J A, Paris S, Monod M, Hamilton A J, Debeaupuis J P, Diaquin M, López-Medrano R, Leal F, Latgé J P
Laboratoire des Aspergillus, Institut Pasteur, Paris, France.
Infect Immun. 1997 Nov;65(11):4718-24. doi: 10.1128/iai.65.11.4718-4724.1997.
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.
烟曲霉拥有两种过氧化氢酶（根据它们的电泳迁移率被描述为快型和慢型）。慢过氧化氢酶已被公认为免疫功能正常患者曲霉病的诊断抗原。抗原性过氧化氢酶已被纯化。该酶是一种由90 kDa亚基组成的四聚体蛋白。相应的cat1基因被克隆，测序数据表明cat1基因编码一个728个氨基酸的多肽。在毕赤酵母中表达的重组蛋白具有酶活性，并且具有与野生型过氧化氢酶相似的生化和抗原特性。分子实验表明，CAT1分别包含一个15个和12个氨基酸残基的信号肽和前肽。无法产生慢过氧化氢酶的cat1基因破坏突变体对过氧化氢和多形核细胞的敏感性与野生型菌株相同。此外，在曲霉病小鼠模型中，cat1突变体与其亲本cat1+菌株之间的致病性没有差异。
