Lv Liangtao, Lin Hong, Li Zhenxing, Ahmed Ishfaq, Chen Guanzhi
Lab of Food Safety, College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong, China.
The Affiliated Hospital of Medical College Qingdao University, Qingdao, Shandong, China.
J Sci Food Agric. 2017 Oct;97(13):4588-4594. doi: 10.1002/jsfa.8328. Epub 2017 May 17.
Stability in simulated gastric fluids is considered an important parameter for the estimation of food allergenicity. Moreover, proteins in food are highly susceptible to lipid oxidation during processing and preservation. In this study, the change in the IgE-binding capacity of malondialdehyde (MDA)-treated shrimp tropomyosin (TM) following in vitro digestion was investigated by SDS-PAGE and western blot.
Shrimp TM treated with different concentrations of MDA was slightly degraded and became increasingly resistant to pepsin digestion over time. While untreated TM was rapidly degraded, MDA-treated TM showed some resistance and was degraded by trypsin only after increasing the digestion time. Results of immunoblotting studies on IgE using sera from patients allergic to shrimp indicated that the IgE-binding capacity of TM and MDA (50 mmol L )-treated TM decreased slightly after pepsin digestion and significantly decreased after trypsin digestion.
The study indicated that the resistance of TM to degradation increased after oxidation. The treatment with proteases, especially trypsin, is quite effective in decreasing the IgG/IgE-binding capacity of shrimp TM. © 2017 Society of Chemical Industry.
模拟胃液中的稳定性被认为是评估食物致敏性的一个重要参数。此外，食品中的蛋白质在加工和保存过程中极易受到脂质氧化的影响。在本研究中，通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和蛋白质免疫印迹法，研究了丙二醛（MDA）处理的虾原肌球蛋白（TM）在体外消化后免疫球蛋白E（IgE）结合能力的变化。
用不同浓度MDA处理的虾TM略有降解，并且随着时间的推移对胃蛋白酶消化的抵抗力增强。未处理的TM迅速降解，而经MDA处理的TM表现出一定的抵抗力，仅在延长消化时间后才被胰蛋白酶降解。使用对虾过敏患者的血清进行的IgE免疫印迹研究结果表明，TM和经MDA（50 mmol/L）处理的TM的IgE结合能力在胃蛋白酶消化后略有下降，在胰蛋白酶消化后显著下降。
该研究表明，氧化后TM的抗降解能力增强。用蛋白酶，尤其是胰蛋白酶处理，对降低虾TM的IgG/IgE结合能力非常有效。©2017化学工业协会。
