Liu Jingbo, Jiang Hongyu, Zhang Min, Yang Meng, Zhang Ting, Du Zhiyang, Xu Menglei, Liu Xuanting
Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun 130062, China.
Jilin Provincial Key Laboratory of Nutrition and Functional Food and College of Food Science and Engineering, Jilin University, Changchun 130062, China.
Food Chem. 2022 Sep 15;388:133030. doi: 10.1016/j.foodchem.2022.133030. Epub 2022 Apr 22.
This study aimed to establish binary protein system on egg white ovalbumin (OVA) -lysozyme (LYS), and investigated the relationship between co-aggregation and co-gelation. We focused on the formation of OVA-LYS complex, the typical thermo-dynamically favored coacervation process, in terms of gelling properties, microstructure and thermodynamics. Benefited from synergistic effects during co-gelation, the thermally induced gels of OVA-LYS complex formed at extremely low protein concentration (18 mg/mL) and showed higher storage modulus with increasing LYS concentration. Moreover, the rising particle size, reduced zeta potential, unordered secondary structure and strengthened protein chain were observed with the addition of LYS. Remarkably, the divalent ions enhanced thermodynamic stability of OVA-LYS complex, although the growth of aggregates units were prevented by ions at room temperature. ITC and molecular docking analyses revealed the binding affinity stoichiometry and combination phase, which were closely related to the decrease of minimum energy resulted from the formation of hydrogen bond.
本研究旨在建立蛋清卵清蛋白（OVA）-溶菌酶（LYS）二元蛋白质体系，并研究共聚集与共凝胶化之间的关系。我们从凝胶特性、微观结构和热力学方面，重点关注OVA-LYS复合物的形成，这是典型的热力学有利的凝聚过程。得益于共凝胶化过程中的协同效应，OVA-LYS复合物的热诱导凝胶在极低的蛋白质浓度（18 mg/mL）下形成，并且随着LYS浓度的增加表现出更高的储能模量。此外，随着LYS的添加，观察到粒径增大、zeta电位降低、二级结构无序以及蛋白质链增强。值得注意的是，二价离子增强了OVA-LYS复合物的热力学稳定性，尽管在室温下离子会阻止聚集体单元的生长。等温滴定量热法（ITC）和分子对接分析揭示了结合亲和力化学计量和结合阶段，这与氢键形成导致的最低能量降低密切相关。
