Aspergillus fumigatus catalases: cloning of an Aspergillus nidulans catalase B homologue and evidence for at least three catalases

Abstract

The presence of catalases in the water soluble fractions of three Aspergillus fumigatus strains was investigated using non-denaturing and denaturing polyacrylamide gel electrophoresis and Western analysis. Using non-denaturing polyacrylamide gel electrophoresis and staining for catalase activity, three separate catalases were identified. An A. fumigatus catalase gene (catB) was cloned from genomic DNA using the Aspergillus niger catR gene as a probe. Polyclonal antibodies were raised to a glutathione S-transferase-CatB fusion product expressed in Escherichia coli. Western analysis indicated that, under denaturing conditions, the polyclonal antibody recognised a 90-kDa band and under non-denaturing conditions, two separate bands were identified. These results indicate that A. fumigatus in addition to CatB, produces at least two other catalases, one of which is similar in size to CatB. The polyclonal antibody was also used to observe catalase expression in mice, experimentally infected with A. fumigatus. Staining was observed heterogeneously throughout the fungal hyphae. This result indicates that catalase is produced by A. fumigatus during invasive aspergillosis.

Blumeria graminis secretes an extracellular catalase during infection of barley: potential role in suppression of host defence

“…Prussian‐Blue‐stained PAGE gels revealed catalase bands at 160 kDa and 80 kDa in non‐denatured and denatured recombinant Bgh CATB samples, respectively. These correspond to the 160‐kDa band detected in recombinant Bgh protein and to the native Bgh 80‐kDa band with an anti‐CATB polyclonal antibody from A. fumigatus (Takasuka et al ., 1999) by Western analysis. Subsequent immunolocalization studies revealed that when the host is present most of the fungal CATB is secreted from the germ tube tips and leaches down on to the host.…”

“…4Bc,d) and host replica surface (no living host present) (Fig. 4Be,f) at 20 hpi, exploiting the A. fumigatus polyclonal antibody anti‐CATB (Takasuka et al ., 1999). On epidermal strips, immunofluorescence was seen around the germ tube tips, more noticeably around the AGT tip (Fig.…”

“…As such, it shows the hallmarks of a secreted catalase and high sequence similarity to other fungal extracellular catalases. Bgh cat B lies phylogenetically closest to Botrytis cinerea cat B (Schouten et al ., 2002) and Claviceps purpurea cat 1 (Garre et al ., 1998a), within the group carrying the Aspergillus fumigatus cat B sequence (Takasuka et al ., 1999). Bgh cat B lies in a different clade from the fungal peroxisomal catalases, from the cluster carrying the catalases of unknown function and more distant from the ‘outgroup’ carrying the Bgh catalase peroxidase ( cpx ) sequence.…”

Update on antifungal drug resistance mechanisms of Aspergillus fumigatus

“…Notably, Aspergillus species have the ability to produce high levels of catalase and hyperoxide dismutase (Takasuka et al, 1999). This phenomenon has already been observed in AMB-resistant C. albicans strains that overproduce catalase and superoxide dismutase and were less sensitive to oxidative agents than AMB-sensitive C. albicans (Warnock et al, 1999;Moore et al, 2000a,b).…”

Multiple Catalase Genes Are Differentially Regulated in Aspergillus nidulans

“…animals than to catalases from eubacteria and plants. In contrast, CatA and CatB, along with other enzymes up to now found only in filamentous fungi and eubacteria, form the largesubunit catalase family (5,8,13,15,23,24,27,37,48). In fact, endosymbiosis and horizontal gene transfer mechanisms have been invoked to explain the grouping of these fungal and bacterial catalases (24).…”