Hao Mengzhen, Wang Qiqi, Wang Junjuan, Che Huilian, Guo XiaoHui, Zhang Yuzhu
College of Food Science and Nutritional Engineering, China Agricultural University, No. 17, Qinghua East Road, Haidian District, Beijing 100083, China.
Institute of Agri-food Processing and Nutrition, Beijing Academy of Agriculture and Forestry Sciences, Beijing Key Laboratory of Fruits and Vegetables Preservation and Processing, Key Laboratory of Vegetable Postharvest Processing, Ministry of Agriculture and Rural Affairs, Beijing 100097, China.
J Agric Food Chem. 2024 Oct 7. doi: 10.1021/acs.jafc.4c04328.
There have been clinical reports of allergies to dragon fruits. However, little is known about the allergens that trigger these reactions. This study aimed to investigate novel allergens in dragon fruits. The peptide mass fingerprints of two purified natural allergens were identified by LC-MS/MS with chymotrypsin proteolysis. The complete amino acid sequences of the allergens were deduced from cDNA amplicon sequences. The coding sequences of two allergens were inserted in the expression vector pColdI, and recombinant allergens were produced in . Circular dichroism was performed to analyze the secondary structures of natural and recombinant allergens. Our results identified two novel allergens as Kunitz-type protease inhibitors. Recombinant allergens exhibited well-folded structures, predominantly composed of β-sheets, similar to their natural counterparts. IgE reactivity analysis with sera from ten patients primarily sensitized to dragon fruit indicated that Kunitz-type protease inhibitors are major allergens in dragon fruits. These results improve our understanding of allergen sources and provide important insights into the allergenicity of proteins from different species.
已有关于火龙果过敏的临床报告。然而，引发这些反应的过敏原却鲜为人知。本研究旨在探究火龙果中的新型过敏原。通过胰凝乳蛋白酶蛋白水解，利用液相色谱-串联质谱法（LC-MS/MS）鉴定了两种纯化的天然过敏原的肽质量指纹图谱。从cDNA扩增子序列推导过敏原的完整氨基酸序列。将两种过敏原的编码序列插入表达载体pColdI中，并在……中产生重组过敏原。进行圆二色性分析以研究天然和重组过敏原的二级结构。我们的结果鉴定出两种新型过敏原为Kunitz型蛋白酶抑制剂。重组过敏原呈现出折叠良好的结构，主要由β-折叠组成，与其天然对应物相似。对十名主要对火龙果致敏患者的血清进行的IgE反应性分析表明，Kunitz型蛋白酶抑制剂是火龙果中的主要过敏原。这些结果增进了我们对过敏原来源的理解，并为不同物种蛋白质的致敏性提供了重要见解。
