CHARACTERIZATION OF A PROTEASE FROM THERMOACTINOMYCES VULGARIS (THERMITASE) .1. INVESTIGATIONS ON PURIFICATION OF THERMITASE

  • 1 January 1978
    • journal article
    • research article
    • Vol. 37  (8) , 1185-1192
Abstract
The microbial protease preparation thermitase (submerged cultivation of T. vulgaris; treatment of culture filtrate with ethanol or Na2SO4, vacuum drying of precipitate) was purified. The crude substance was purified by column chromatography on Sephadex G-75, DEAE-Cellulose and Sephadex G-50. The proteolytically active fractions were in each case united, freeze dried and tested for protein components and protease activity by gel electrophoresis. After passage of the 3rd column, the isolated protease (4.5-fold enrichment in the specific activity) was further characterized. The electropherogram (pH 8.9) presented a protease band moving to the anode which was accompanied by 2 very weak protease bands. A very active protease band (main component of thermitase) and a side band with lower activity both moving to the cathode were detected. The freeze-dried preparation contained 85% protein and 4% carbohydrates (glucose as single monomer component after acid hydrolysis). A MW of 11,000 was determined by chromatography on Sephadex G-75. This value is critically discussed. Hints are given for autolytic processes taking place during the purification procedure.