Purification and characterization of a 43.5 kDa keratinolytic metalloprotease from Microsporum canis.
A keratinolytic protease secreted by a feline clinical isolate of Microsporum canis cultivated in a broth containing feline keratin as the sole nitrogen source was purified from the culture filtrate by affinity chromatography on bacitracin-agarose and by hydrophobic chromatography on octyl-agarose. The enzyme had an apparent molecular mass of 43.5 kDa and the pI was 7.7. It had a significant activity against keratin azure, elastin-Congo red and denatured type I collagen (azocoll). Using the latter substrate, the optimum pH was around 8 and the apparent optimum temperature around 50 degrees C. The protease was strongly inhibited by 1,10-phenanthroline, phosphoramidon and EDTA. The first 13 N-terminal amino acid sequence showed a 61% homology with that of the extracellular metalloprotease of Aspergillus fumigatus and with the neutral protease I of A. oryzae, confirming that this 43.5 kDa keratinase is a metalloprotease. This keratinolytic metalloprotease could be a virulence-related factor involved in pathophysiological mechanisms of M. canis dermatophytosis.
Brouta
F
F
Department of Parasitology & Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, Belgium.
Descamps
F
F
Fett
T
T
Losson
B
B
Gerday
C
C
Mignon
B
B
D000595:Amino Acid Sequence; D000818:Animals; D002371:Cat Diseases / Q000382:microbiology*; D002415:Cats; D003881:Dermatomycoses / Q000382:microbiology / Q000662:veterinary*; D004591:Electrophoresis, Polyacrylamide Gel; D007633:Keratins / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D008864:Microsporum / Q000201:enzymology* / Q000254:growth & development / Q000302:isolation & purification; D008969:Molecular Sequence Data
D007633:Keratins; D008666:Metalloendopeptidases