title: Inducible chitinolytic system of Aspergillus fumigatus.
abstract: Incubation of Aspergillus fumigatus NCPF 2140 in growth medium containing 1% chitin as sole carbon source led to induction of specific extracellular chitinolytic activity of 1.5 mumol GlcNAc released min-1 (mg protein)-1. The effect was repressed by the inclusion of GlcNAc in the medium, indicating regulation by a negative feedback mechanism. Extracellular chitinase activity was inhibited by allosamidin (IC50 0.12 microM). Multiple chitinolytic enzymes were detected on zymograms of extracellular preparations; levels of individual enzymes induced were dependent upon whether cells were incubated with purified colloidal chitin or a crude preparation of crystalline chitin. A major, inducible, 45 kDa chitinase was purified using ammonium sulphate precipitation, chitin affinity chromatography and a novel procedure involving the electroelution of the enzyme from a substrate gel containing glycol chitin. The enzyme is a glycoprotein with endochitinase activity.
authors.affiliation: Department of Microbiology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Gemma M
authors.initials: GM
authors.lastname: Escott
authors.affiliation: Department of Microbiology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Veronica M
authors.initials: VM
authors.lastname: Hearn
authors.affiliation: Department of Microbiology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Adams
mesh_terms: D000117:Acetylglucosamine / Q000494:pharmacology; D000595:Amino Acid Sequence; D001232:Aspergillus fumigatus / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D002686:Chitin / Q000378:metabolism / Q000494:pharmacology; D002688:Chitinases / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000187:drug effects; D005656:Fungal Proteins / Q000032:analysis* / Q000378:metabolism; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013997:Time Factors
chemical_list: D005656:Fungal Proteins; D002686:Chitin; D002688:Chitinases; D000117:Acetylglucosamine