Abstract
Although the pathogenic factors and mechanisms in fungal infection are not yet fully understood, many investigators have pointed out the important role of fungus in producing extracellular proteinases. The present study demonstrated the characteristics of Sporothrix schenckii in producing proteinases and identified the roles of proteinases in the pathogenesis of sporothrichosis. (1) S. schenckii produced extracellular proteinases to catalyze albumin, collagen, elastin, keratin and so forth. (2) Proteinases were produced in culture media containing these substrates, but were not produced in Sabouraud's medium. (3) Two proteinases (proteinase I and II) were purified. Proteinase I was Mr 36, 500, pH optima 6.0 and serine proteinase inhibited by chymostatin. Proteinase II was Mr 39, 000, pH optima 3.5 and carboxyl proteinase inhibited by pepstatin. (4) Neither proteinase I nor II was produced nor were cells grown in culture when pepstatin or chymostatin was added. (5) Cell growth was not inhibited in culture by addition of either pepstatin or chymostatin. (6) S. schenckii infection was suppressed in vivo (mouse model) by the application of both inhibitors.
These results conclude that the 2 proteinases produced by S. schenckii work cooperatively and compensatively in S. schenckii infection.
