纤维素酶纤维素吸附区的结构与功能

大多数纤维素酶含有催化区和可与纤维素结合且氨基酸序列较为保守的纤维素吸附区(cellulosebindingdomain,CBD)。纤维素吸附区促进酶与底物的结合,有利于催化区对不溶性底物的作用,但对可溶性底物的催化作用无影响。对CBD结构的研究和进一步的诱变研究揭示:纤维素吸附区是通过几个芳香族氨基酸结合到纤维素表面。有实验证明外切葡聚糖酶的CBD对结晶纤维素有疏解作用。CBD结构域已成功地应用于一系列重组融合蛋白的纯化和固定化。对纤维素吸附区结构与功能的深入了解对进一步了解酶的作用机制,促进纤维素酶类生物技术的发展是重要的 。

The Structure and Function of Cellulose-binding Domain of Microbiological Cellulase

Most cellulases consist of catalytic domains and cellulose binding domains(CBDs),which can bind to cellulose and are conserved in some amino acid sequences.Cellulose binding domains improve the binding and facilitate the activity of catalytic domains on the insoluble substrate,but not on soluble substrate.The results of investigations on structure and function,and subsequent mutagenesis of the CBDs indicated that CBDs rely on several aromatic amino acids for binding to the cellulose surfaces.Some experiment results showed that CBDs of exoglucanases are able to disrupt the crystalline cellulose,facilitate the enzymatic degradation of cellulose.The structural domain as CBDs has been successfully used in purification and immobilization of numerous examples of fusion proteins.The improved undersdanding of the structure and function of CBDs are significant to undersdanding of enzymatic functionary mechanism,and the development of cellulase biotechnology.