Research Unit VEG-i-TEC, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Campus Kortrijk, Sint-Martens-Latemlaan 2B, 8500 Kortrijk, Belgium.
Ultrason Sonochem. 2023 Dec;101:106720. doi: 10.1016/j.ultsonch.2023.106720. Epub 2023 Dec 9.
Considering the growing interest in enzyme-based extraction technology as a safe and eco-friendly extraction technique, along with the relatively high cost associated with enzymatic applications, it became necessary to explore novel strategies aimed to improve enzyme activity. In this study, the impact of ultrasonic treatment on commercial cellulase and pectinase was investigated. As this effect may be influenced by various ultrasonic and enzyme-related parameters, changes in enzyme conformation were explored under optimal and non-optimal enzyme conditions. The intrinsic fluorescence spectrum was utilized as a tool for monitoring these changes. Additionally, the enzyme's catalytic potential was also assessed under the same conditions. Results indicated that the impact of ultrasonic treatment on enzyme conformation primarily depends on the total ultrasonic energy delivered to the system, rather than other ultrasonic parameters such as power, sample volume, treatment time, or duty cycle. The maximum relative decrease in intrinsic fluorescence intensity of Pectinex® Ultra Clear (PUC) and Pectinex® Ultra SPL (PUS) after ultrasonic treatment was approximately 51% and 55%, respectively, while the decrease induced by thermal denaturation was 25% and 30% respectively. Furthermore, a blue shift in the fluorescence spectrum of both pectinases was observed upon sonication for all process conditions indicating a change in enzyme conformation. However, ultrasonic treatment did not result in a significant change in enzyme activity, suggesting that these conformational adjustments may occur in regions other than the active sites. Moreover, ultrasonicated pectinases and cellulases did not exhibit any improvement in their catalytic potential under either optimal or non-optimal conditions.
鉴于人们对基于酶的提取技术越来越感兴趣，因为它是一种安全且环保的提取技术，而且酶应用的成本相对较高，因此有必要探索旨在提高酶活性的新策略。在这项研究中，研究了超声处理对商业纤维素酶和果胶酶的影响。由于这种影响可能受到各种超声和酶相关参数的影响，因此在最佳和非最佳酶条件下探索了酶构象的变化。利用内源荧光光谱作为监测这些变化的工具。此外，还在相同条件下评估了酶的催化潜力。结果表明，超声处理对酶构象的影响主要取决于传递给系统的总超声能，而不是其他超声参数，如功率、样品体积、处理时间或占空比。超声处理后 Pectinex®Ultra Clear（PUC）和 Pectinex®Ultra SPL（PUS）的内源荧光强度最大相对降低分别约为 51%和 55%，而热变性引起的降低分别为 25%和 30%。此外，在所有处理条件下，两种果胶酶的荧光光谱均观察到蓝移，表明酶构象发生变化。然而，超声处理并没有导致酶活性发生显著变化，这表明这些构象调整可能发生在活性部位之外的区域。此外，超声处理的果胶酶和纤维素酶在最佳和非最佳条件下均未表现出催化潜力的任何提高。
