Purification and characterization of a 43.5 kDa keratinolytic metalloprotease from Microsporum canis

• Published in: Medical mycology (Oxford) Vol. 39; no. 3; p. 269
• Main Authors: Brouta, F, Descamps, F, Fett, T, Losson, B, Gerday, C, Mignon, B
• Format: Journal Article
• Language: English
• Published: England 01.06.2001
• Subjects: Amino Acid Sequence; Animals; Cat Diseases - microbiology; Cats; Dermatomycoses - microbiology; Dermatomycoses - veterinary; Electrophoresis, Polyacrylamide Gel; Keratins - metabolism; Metalloendopeptidases - antagonists & inhibitors; Metalloendopeptidases - chemistry; Metalloendopeptidases - isolation & purification; Metalloendopeptidases - metabolism; Microsporum - enzymology; Microsporum - growth & development; Microsporum - isolation & purification; Molecular Sequence Data
• ISSN: 1369-3786; 1460-2709
• DOI: 10.1080/mmy.39.3.269.275

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.