Partial purification and some biochemical characteristics of exocellular keratinase from Trichophyton mentagrophytes var. erinacei.

The dermatophyte Trichophyton mentagrophytes var. erinacei isolated from patients infected with tinea cruris was cultured in Sabouraud dextrose broth, from which an exocellular keratinase extract was obtained. The keratinase was partially purified with sephadix G-100 gel filtration. Some biochemical characteristics of the purified enzyme were examined. Its molecular weight was estimated to be 38,000 dalton on sodium dodecyle sulfate polyacrylmide gel electrophoresis (SDS-PAGE). The optimal pH was 5.5 and optimal temperature for the highest keratinase activity was 50 degrees C. The enzyme activity was specifically increased against guinea pig hair and fibrous protein and inhibited by phenylmethylsulfonylfluoride.