Pan Fengguang, Wu Xinling, Gong Lingling, Xu Haojie, Yuan Yixin, Lu Jinming, Zhang Ting, Liu Jingbo, Shang Xiaomin
Jilin Provincial Key Laboratory of Nutrition and Functional Food, Jilin University, Changchun 130062, PR China; College of Food Science and Engineering, Jilin University, Changchun 130062, PR China.
College of Food Science and Engineering, Jilin University, Changchun 130062, PR China.
Food Chem. 2024 Jul 1;445:138720. doi: 10.1016/j.foodchem.2024.138720. Epub 2024 Feb 12.
The tendency of ovotransferrin (OVT) to unfold and aggregate under 60 °C severely restricted sterilization temperature during egg processing. Searching for efficient strategies to improve OVT thermal stability is essential for improving egg product quality and processing suitability. Here, we investigated the effect of sulfate polysaccharide (dextran sulfate, DS) on heat-induced aggregation of OVT. We found that DS can effectively suppress amorphous aggregation of OVT at pH 7.0 after heating. Strikingly, the addition of 5 µM DS fully suppressed insoluble aggregates formation of 0.5 mg/mL OVT. Structure analysis confirmed that DS preserves nearly the entire secondary and tertiary structure of OVT during heating. The steric hindrance effect arising from strong electrostatic interactions between OVT and DS, coupled with reduced OVT hydrophobicity, is the underlying mechanism in suppressing protein-protein interactions, thus enhancing thermal stability. These findings suggest DS could act as protein stabilizers and chaperones, enhancing the thermostability of heat-sensitive proteins.
卵转铁蛋白（OVT）在60°C下易展开并聚集的特性严重限制了蛋制品加工过程中的杀菌温度。寻找提高OVT热稳定性的有效策略对于提高蛋制品质量和加工适用性至关重要。在此，我们研究了硫酸多糖（硫酸葡聚糖，DS）对OVT热诱导聚集的影响。我们发现，加热后，DS能有效抑制pH 7.0条件下OVT的无定形聚集。令人惊讶的是，添加5µM DS可完全抑制0.5mg/mL OVT不溶性聚集体的形成。结构分析证实，加热过程中DS保留了OVT几乎全部的二级和三级结构。OVT与DS之间强烈静电相互作用产生的空间位阻效应，以及OVT疏水性的降低，是抑制蛋白质-蛋白质相互作用从而增强热稳定性的潜在机制。这些发现表明，DS可作为蛋白质稳定剂和伴侣蛋白，提高热敏蛋白的热稳定性。
