Interactions of Endoglucanases with Amorphous Cellulose Films Resolved by Neutron Reflectometry and Quartz Crystal Microbalance with Dissipation Monitoring
Interactions of Endoglucanases with Amorphous Cellulose Films Resolved by Neutron Reflectometry and Quartz Crystal Microbalance with Dissipation Monitoring
复制标题
DOI：
10.1021/la300955q
复制
发表时间：
2012-06-05
期刊：
影响因子：
3.9
通讯作者：
Kent, Michael S.
中科院分区：
文献类型：
--
作者：
Cheng, Gang;Datta, Supratim;Kent, Michael S.
报道了通过中子反射计 (NR) 和带有耗散监测的石英晶体微天平 (QCM-D) 对四种内切葡聚糖酶与无定形纤维素膜的相互作用进行的研究。内切葡聚糖酶包括嗜温真菌内切葡聚糖酶（来自 H. insolens 的 Cel45A）、来自海洋细菌的持续内切葡聚糖酶（来自 S. degradans 的 CelSH）和两种来自嗜热细菌的内切葡聚糖酶（来自 A. Acidocaldarius 的 Cel9A 和来自 T. maritima 的 Cel5A）。无定形纤维素的使用源于离子液体预处理作为第二代技术的前景，该技术破坏了纤维素的天然晶体结构。内切葡聚糖酶表现出高度多样化的行为。具有碳水化合物结合模块 (CBM) 的 Cel4SA 和 Cel5H 比缺乏 CBM 的 Cel9A 和 Cel5A 更能在大部分薄膜中渗透和消化。虽然 Cel45A 和 Cel5H 在大部分薄膜中都很活跃，但观察到了显着的差异。对于 Cel45A，观察到显着的膜膨胀和界面变宽，而对于 Cel5H，膜厚度减小，而界面变宽很小。这些结果与 Cel45A 作为经典内切葡聚糖酶在纤维素链内部消化的情况一致，而 Cel5H 主要在链末端消化与其作为持续内切葡聚糖酶的名称一致。
A study of the interaction of four endoglucanases with amorphous cellulose films by neutron reflectometry (NR) and quartz crystal microbalance with dissipation monitoring (QCM-D) is reported. The endoglucanases include a mesophilic fungal endoglucanase (Cel45A from H. insolens), a processive endoglucanase from a marine bacterium (CelSH from S. degradans), and two from thermophilic bacteria (Cel9A from A. acidocaldarius and Cel5A from T. maritima). The use of amorphous cellulose is motivated by the promise of ionic liquid pretreatment as a second generation technology that disrupts the native crystalline structure of cellulose. The endoglucanases displayed highly diverse behavior. Cel4SA and Cel5H, which possess carbohydrate-binding modules (CBMs), penetrated and digested within the bulk of the films to a far greater extent than Cel9A and Cel5A, which lack CBMs. While both Cel45A and Cel5H were active within the bulk of the films, striking differences were observed. With Cel45A, substantial film expansion and interfacial broadening were observed, whereas for Cel5H the film thickness decreased with little interfacial broadening. These results are consistent with Cel45A digesting within the interior of cellulose chains as a classic endoglucanase, and Cel5H digesting predominantly at chain ends consistent with its designation as a processive endoglucanase.