Partial Purification and Characterization of 41 kDa Serine Proteinase from Culture Filtrate of Trichophyton tonsurans

ABSTRACT

Dermatophytes infect the human hair, skin, nail and cause the dermatophytosis. The extracellular and intracellular proteinases of the dermatophytes commonly occur in the genus Trichophyton like T. rubrum, T. mentagrophytes, and T. granulosum. These enzymes play a prominent role in growth, multiplication and infection of the host tissue. Extracellular proteinases have been purified from the species of Trichophyton and Microsporum. We purified the proteinase partially from the culture filtrate of the Trichophyton tonsurans through Mono-Q and Superose 12 column and investigated its biochemical and enzymatic characters. The molecular size of the proteinase was estimated to be 41 kDa by SDS-PAGE. And pI was 3.2. The optimal temperature and pH for an enzymatic activity were 27C and 7.5, respectively. The purified porteinase degraded the keratin, bovine serum albumin, hemoglobin. The serine proteinase inhibitor like PMSF and DFP inhibited the proteolytic activity of the purified enzyme whereas the cysteinase inhibitor did not. These results demonstrated that the purified proteinase is a serine proteinase and can contribute the tissue invasion.