Activation of crystalline cellulose to cellulose IIII results in efficient hydrolysis by cellobiohydrolase
Activation of crystalline cellulose to cellulose IIII results in efficient hydrolysis by cellobiohydrolase
复制标题
DOI：
10.1111/j.1742-4658.2007.05727.x
复制
发表时间：
2007-04-01
期刊：
影响因子：
5.4
通讯作者：
Samejima, Masahiro
中科院分区：
文献类型：
--
作者：
Igarashi, Kiyohiko;Wada, Masahisa;Samejima, Masahiro
通过超临界铵和水热处理分别将绿色真菌刚毛藻的纤维素（富含纤维素I-α）的多晶型转化为纤维素IIII和I-β，并通过基于酶表面密度的新分析评估绿色木霉纤维二糖水解酶I（Cel 7A）在这些产物上的水解速率和吸附。纤维素IIII的纤维二糖产量是纤维素I的5倍以上。然而，纤维素IIII上吸附的酶量不到纤维素I上的两倍，并且纤维素IIII的吸附酶的比活性比纤维素I高3倍以上。当通过水热处理将纤维素IIII转化为纤维素I-β时，纤维二糖的产量显著降低，尽管在酶吸附中没有观察到显著变化。这清楚地表明纤维素IIII的增强的水解与结晶多晶型物的结构有关。因此，超临界铵处理活化结晶纤维素以供纤维二糖水解酶水解。
The crystalline polymorphic form of cellulose (cellulose I-alpha-rich) of the green alga, Cladophora, was converted into cellulose IIII and I-beta by supercritical ammonium and hydrothermal treatments, respectively, and the hydrolytic rate and the adsorption of Trichoderma viride cellobiohydrolase I (Cel7A) on these products were evaluated by a novel analysis based on the surface density of the enzyme. Cellobiose production from cellulose IIII was more than 5 times higher than that from cellulose I. However, the amount of enzyme adsorbed on cellulose IIII was less than twice that on cellulose I, and the specific activity of the adsorbed enzyme for cellulose IIII was more than 3 times higher than that for cellulose I. When cellulose IIII was converted into cellulose I-beta by hydrothermal treatment, cellobiose production was dramatically decreased, although no significant change was observed in enzyme adsorption. This clearly indicates that the enhanced hydrolysis of cellulose IIII is related to the structure of the crystalline polymorph. Thus, supercritical ammonium treatment activates crystalline cellulose for hydrolysis by cellobiohydrolase.