PURIFICATION AND PROPERTIES OF ENDOGLUCANASES FROM ASPERGILIUS ACULEATUS SM-L22
脱墨用棘孢曲霉SM-L22纤维素酶系中内切酶的纯化及性质

The five endoglucanases(CMCase) components from Aspergillus aculeatus SM-L22 were separated and purified by exclusion chromatography and ion-exchange chromatography. Five components(EG II-1, EG II-2, EG III-1, EG III-2 and EG IV) had molecular weights of 38.7, 34.4, 31.4, 36.9 and 23.7 kD by SDS-PAGE, respectively, and IEF showed their pI were pH < 3.5, < 3.5, 4.9, 4.4 and 5.0, respectively. All of them have maximum reactive activities at pH 3.5-4.0; and the optimum temperatures were 55 degrees C, 60 degrees C, 60 degrees C-70 degrees C, 60 degrees C-70 degrees C and 60 degrees C, respectively. EG II-1 and EG II-2 can only act such morphological substrates as CMC or phosphated cellulose, but EG III-1, EG III-2 and EG IV can active xylan also. The activities of all components were stimulated by Fe2+ except EG IV, EG III-2 was activited mostly by Fe2+. The kinetics' showed that there were no relativies between the affectivity of cellulases and its Km.