Guo Dashan, Hou Yuwei, Liang Hongshan, Han Lingyu, Li Bin, Zhou Bin
Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, School of Biological Engineering and Food, Hubei University of Technology, Wuhan 430068, China.
College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Foods. 2023 May 9;12(10):1931. doi: 10.3390/foods12101931.
The distinctive assembly behaviors of lysozyme (Lys) feature prominently in food, materials, biomedicine, and other fields and have intrigued many scholars. Although our previous work suggested that reduced glutathione (GSH) could induce lysozyme to form interfacial films at the air/water interface, the underlying mechanism is still obscure. In the present study, the effects of GSH on the disulfide bond and protein conformation of lysozyme were investigated by fluorescence spectroscopy, circular dichroism spectroscopy, and infrared spectroscopy. The findings demonstrated that GSH was able to break the disulfide bond in lysozyme molecules through the sulfhydryl/disulfide bond exchange reaction, thereby unraveling the lysozyme. The β-sheet structure of lysozyme expanded significantly, while the contents of α-helix and β-turn decreased. Furthermore, the interfacial tension and morphology analysis supported that the unfolded lysozyme tended to arrange macroscopic interfacial films at the air/water interface. It was found that pH and GSH concentrations had an impact on the aforementioned processes, with higher pH or GSH levels having a positive effect. This paper on the exploration of the mechanism of GSH-induced lysozyme interface assembly and the development of lysozyme-based green coatings has better instructive significance.
溶菌酶（Lys）独特的组装行为在食品、材料、生物医学等领域具有突出表现，吸引了众多学者的关注。尽管我们之前的研究表明，还原型谷胱甘肽（GSH）可诱导溶菌酶在空气/水界面形成界面膜，但其潜在机制仍不清楚。在本研究中，通过荧光光谱、圆二色光谱和红外光谱研究了GSH对溶菌酶二硫键和蛋白质构象的影响。研究结果表明，GSH能够通过巯基/二硫键交换反应打破溶菌酶分子中的二硫键，从而使溶菌酶解折叠。溶菌酶的β-折叠结构显著扩展，而α-螺旋和β-转角的含量降低。此外，界面张力和形态分析表明，解折叠的溶菌酶倾向于在空气/水界面排列形成宏观界面膜。研究发现，pH值和GSH浓度对上述过程有影响，较高的pH值或GSH水平具有积极作用。本文对GSH诱导溶菌酶界面组装机制的探索以及基于溶菌酶的绿色涂层的开发具有较好的指导意义。
