The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China.
The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China; Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China.
Food Chem. 2016 Jul 1;202:49-58. doi: 10.1016/j.foodchem.2016.01.119. Epub 2016 Jan 28.
The interactions between pullulanase and chitosans of different molecular weights (Mw) were comprehensively studied, and their applications in pullulanase immobilization onto Fe3O4-κ-carrageenan nanoparticles upon chitosan-pullulanase complexation were also evaluated. Chitosan (CS) complexation with pullulanase was found to be dependent on pH and chitosan Mw. The critical pH of structure-forming events during complexation shifted significantly (p<0.05) to a lower pH with a low Mw chitosan (50kDa) compared to other chitosan types. Binding constants for the chitosan-pullulanase interaction increased in the following order: CS-500<CS-400<CS-50<CS-200. The binding induced alterations in the protein secondary structure, which may affect the enzymatic properties of immobilized pullulanase. Pullulanase immobilized upon CS-50 complexation exhibited the most desirable enzymatic properties. These results indicated that the complexation behavior was mainly dependent on chitosan Mw. This study presents a technique for the production of immobilized pullulanase upon complexation that exhibits potential for applications in continuous syrup production.
本文全面研究了普鲁兰酶与不同分子量（Mw）壳聚糖之间的相互作用，并评估了它们在壳聚糖-普鲁兰酶复合物作用下将普鲁兰酶固定到 Fe3O4-κ-卡拉胶纳米粒子上的应用。发现壳聚糖（CS）与普鲁兰酶的复合取决于 pH 值和壳聚糖 Mw。与其他壳聚糖类型相比，低 Mw 壳聚糖（50kDa）的结构形成事件的临界 pH 值明显（p<0.05）向更低的 pH 值移动。壳聚糖-普鲁兰酶相互作用的结合常数按以下顺序增加：CS-500<CS-400<CS-50<CS-200。结合诱导了蛋白质二级结构的变化，这可能会影响固定化普鲁兰酶的酶学性质。CS-50 复合固定化的普鲁兰酶表现出最理想的酶学性质。这些结果表明，复合行为主要取决于壳聚糖 Mw。本研究提出了一种通过复合生产固定化普鲁兰酶的技术，该技术在连续糖浆生产中具有潜在应用。
