Partial Proteolysis of Some Cellulase Components from Trichoderma viride and the Substrate Specificity of the Modified Products

Abstract

An endo-cellulase component [EC 3. 2.1.4] of random type; F II, was obtained from “Cellulase Onozuka, ” a commercial product from Trichoderma viride, and was subjected to partial proteolysis with a protease preparation of the same fungal origin. The resulting modified cellulase was fractionated by two steps of column chromatog-raphy, and the resulting patterns, together with the substrate specificity expressed in terms of the randomness of CMC hydrolysis and the immunological properties against anti-F II-rabbit serum, were examined. The chromatographic patterns were very similar to those of cellulase subtractions without proteolytic treatment. Moreover, the immunological response of the modified cellulases from F II was mostly positive and their randomness of CMC hydrolysis was generally lower, compared with sub-fractions of F II which were not subjected to proteolysis. The subfractions of Peak III, which were obtained from F II by proteolysis, showed mostly negative immunological response and higher randomness of CMC hydrolysis compared with sub-factions of Peak III which were not subjected to proteolysis. Thus, some limited proteolysis of cellulase components may, at least in part, be responsible for its multiplicity in vivo.