Cellulase complex from Chaetomium cellulolyticum: isolation and properties of major components

Four major components of the cellulase complex of Chaetomium cellulolyticum have been isolated by gel-filtration, ion-exchange chromatography on DEAE-Toyopearl and Macro Prep Q, and chromatofocusing on Mono P. These components include three endoglucanases (19, 35, and 40 kD) and a cellobiohydrolase (45 kD). The isoelectric points of the enzymes vary from 3.8 to 4.2. The optimal pH values for catalytic activity are in the range 4.5-6.0, and the optimal temperatures are in the range 60-70 degrees C. Of these enzymes the 19 kD endoglucanase is the most stable; it retained high activity within a broad pH range (from 5.0 to 9.6) at 50 degrees C for 3 h. This enzyme also had the highest topolytic activity determined by the efficiency of removal of indigo from the surface of cotton.