Zhang Jiangtao, Liu Wenying, Fang Lei, Gu Ruizeng, Lu Jun, Li Guoming
Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing 100015, PR China.
Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing 100015, PR China.
Allergol Immunopathol (Madr). 2020 Jan-Feb;48(1):26-33. doi: 10.1016/j.aller.2019.08.001. Epub 2019 Oct 14.
The production and consumption of oysters is increasing annually because it can provide essential nutrients and benefit for human health, leading to frequent occurrence of severe allergic reactions observed in sensitized individuals. The aim of the present study was to investigate the effects of acid and protease treatment on the conformation and IgE-binding capacity of recombinant Crassostrea gigas tropomyosin (Cra g 1).
Under acidic conditions, Cra g 1 did not undergo degradation, however, the changes obvious in the intensity of CD signal and ANS-binding fluorescence were observed, which was associated with a decrease in antibody reactivity. In simulated gastrointestinal fluid (SGF) and simulated intestinal fluid (SIF) digestion system, acid-treated Cra g 1 was relatively resistant to digestion, but the degradative patterns were very different. Moreover, owing to alterations of secondary structure and hydrophobic surface of the protein during digestive processing, antigenicity of acid-induced Cra g 1 reduced in SGF while it increased significantly in SIF.
To our knowledge, this is the first study reporting that antigenicity of acid-treated oyster tropomyosin increased after SIF digestion. These results revealed that treatment with acid and pepsin, rather than trypsin, was an effective way of reducing IgE-binding capacity of tropomyosin from oyster.
牡蛎的产量和消费量逐年增加，因为它能提供必需营养素并对人类健康有益，但这也导致致敏个体中严重过敏反应频繁发生。本研究的目的是探究酸和蛋白酶处理对重组太平洋牡蛎原肌球蛋白（Cra g 1）的构象和IgE结合能力的影响。
在酸性条件下，Cra g 1未发生降解，然而，观察到CD信号强度和ANS结合荧光有明显变化，这与抗体反应性降低有关。在模拟胃肠液（SGF）和模拟肠液（SIF）消化系统中，酸处理的Cra g 1对消化相对具有抗性，但降解模式非常不同。此外，由于消化过程中蛋白质二级结构和疏水表面的改变，酸诱导的Cra g 1在SGF中的抗原性降低，而在SIF中显著增加。
据我们所知，这是第一项报道酸处理的牡蛎原肌球蛋白在SIF消化后抗原性增加的研究。这些结果表明，用酸和胃蛋白酶而非胰蛋白酶处理是降低牡蛎原肌球蛋白IgE结合能力的有效方法。
