Isolation and Characterization of Keratinases from Different Kinds of Dermatophytes

Background : Several groups of workers have isolated and purified the keratinolytic proteinases from some species of dermatophytoses. But it is not efficient to compare the interspecies of dermatophytosis because the separation and purification are done by different conditions. Objective : To compare the characteristics and difference of the keratinases which are isolated and purified from Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis in the same conditions. Methods : Proteinases elaborated from T. rubrum, T. mentagrophytes and M. canis were purified by precipitation using ammonium sulfate and by SMART. SDS-polyacrylamide gel electrophoresis was carried out, and the effect of various inhibitors was investigated. A variety of substrates for KPase were tested. Results : 1. The keratinases were isolated and purified 17.3, 22.0, 17.6-fold from T. rubrum, T. mentagrophytes and M. canis. 2. Each molecular weight of the keratinolytic proteinases isolated and purified from T. rubrum, T. mentagrophytes and M. canis was 53 kDa, 65 kDa, 77 kDa. 3. Phenylmethylsulfonylfluoride inhibited the keratinase activity in T. rubrum, T. mentagrophytes and M. canis 4. The keratinases from T. rubrum, T. mentagrophytes and M. canis digested much more human stratum corneum and human nail than human scalp hair, but keratinase from M. canis digested much more human scalp hair than human stratum corneum and human nail. Conclusion: The results show keratinases from T. rubrum, T. mentagrophytes and M. canis were different each other, but they may be a kind of serine proteinase. The keratinases from T. rubrum, T. mentagrophytes and M. canis may play an important role in tinea pedis and tinea unguis by affecting the human stratum corneum and human nail, and the keratinase from M. canis may play an important role in tinea capitis by affecting the human hair.ope