A 25-kDa serine peptidase with keratinolytic activity secreted by Coccidioides immitis.
Coccidioides immitis is the causative agent of coccidioidomycosis, a systemic mycosis that attacks humans and a wide variety of animals. In the present study, we showed that the C. immitis mycelial form is able to release proteolytic enzyme into the extracellular environment. Under chemically defined growth conditions, mycelia secreted seven distinct polypeptides ranging from 15 to 65 kDa and an extracellular peptidase of 25 kDa. This enzyme had its activity fully inhibited by phenylmethylsulphonyl fluoride, a serine peptidase inhibitor. Conversely, metallo, cysteine, and aspartyl peptidase inhibitors did not alter the 25-kDa enzyme behavior. This extracellular serine peptidase was able to degrade keratin, a fibrous protein that composes human epidermis. Additionally, this peptidase cleaved different protein substrates, including gelatin, casein, hemoglobin, and albumin. Curiously, an 18-kDa serine peptidase activity was evidenced solely when casein was used as the co-polymerized protein substrate into the gel. The existence of different secreted peptidases could be advantageous for the adaptation of C. immitis to distinct environments during its complex life cycle.
Lopes
Bárbara Gabriela Brum
BG
Departamento de Microbiologia Geral, Instituto de Microbiologia Prof. Paulo de Góes (IMPPG), Centro de Ciências da Saúde (CCS), Universidade Federal do Rio de Janeiro (UFRJ), Ilha do Fundão, Rio de Janeiro 21941-902, RJ, Brazil.
Santos
André Luis Souza Dos
AL
Bezerra
Cláudia de Carvalho Falci
Cde C
Wanke
Bodo
B
Dos Santos Lazéra
Márcia
M
Nishikawa
Marília Martins
MM
Mazotto
Ana Maria
AM
Kussumi
Vânia Monteiro
VM
Haido
Rosa Maria Tavares
RM
Vermelho
Alane Beatriz
AB
D000818:Animals; D001938:Brazil; D003045:Coccidioides / Q000201:enzymology* / Q000302:isolation & purification / Q000472:pathogenicity; D003047:Coccidioidomycosis / Q000382:microbiology; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000737:chemistry / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism*
D005656:Fungal Proteins; D010447:Peptide Hydrolases; C035855:keratinase; D012697:Serine Endopeptidases