Partial purification and kinetic studies of exocellular proteinase from Trichophyton mentagrophytes var. erinacei

The dermatophyte Trichophyton mentagrophytes var. erinacei isolated from a patient with tinea cruris was cultured in peptone-glucose broth from which an exocellular proteinase was obtained. The enzyme was partly purified by Sephadex G-100 gel filtration. Its molecular weight was determined to be 33,000 on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal pH was 8.5, the optimal temperature 35 degrees C. The proteolytic activity was specifically increased against casein and inhibited by phenylmethylsulphonyl fluoride. The enzyme was identified as alkaline serine proteinase.