Chen G, Du J, Zhuang L, Gao P
State Key Laboratory of Microbial Technology, Shandong University, Jinan 250010, China.
Wei Sheng Wu Xue Bao. 2001 Aug;41(4):469-74.
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.
通过排阻色谱法和离子交换色谱法对棘孢曲霉SM-L22的5种内切葡聚糖酶(CMCase)组分进行了分离和纯化。通过SDS-PAGE分析,5种组分(EG II-1、EG II-2、EG III-1、EG III-2和EG IV)的分子量分别为38.7、34.4、31.4、36.9和23.7 kD,等电聚焦显示它们的pI分别为pH < 3.5、< 3.5、4.9、4.4和5.0。它们在pH 3.5 - 4.0时均具有最大反应活性;最适温度分别为55℃、60℃、60℃ - 70℃、60℃ - 70℃和60℃。EG II-1和EG II-2仅作用于诸如CMC或磷酸化纤维素等形态学底物,但EG III-1、EG III-2和EG IV也能作用于木聚糖。除EG IV外,所有组分的活性均受到Fe2+的刺激,EG III-2受Fe2+的激活作用最为明显。动力学研究表明,纤维素酶的活性与其Km之间没有相关性。