Laboratory of Biochemistry and Molecular Biology, College of Life Science, Northwest A&F University, Yangling, China.
Laboratory of Biochemistry and Molecular Biology, College of Life Science, Northwest A&F University, Yangling, China.
Mol Immunol. 2018 Feb;94:121-130. doi: 10.1016/j.molimm.2017.12.024. Epub 2018 Jan 4.
Tartary buckwheat (Fagopyrum tataricum, TB) is an important functional food containing proteins with balanced amino acid composition and more flavonoids than common buckwheat (Fagopyrum esculentum, CB). Buckwheat contains highly potent allergens that trigger an allergic reaction via an IgE mediated response. In this work, the full-length cDNA encoding Fag t 2 from tartary buckwheat seeds was cloned by screening the cDNA library of seed-filling period. The recombinant Fag t 2 (rFag t 2) expressed in Pichia pastoris SMD1168H was purified by purified by immobilized metal affinity chromatography. It demonstrated that Fag t 2 was a major allergen in tartary buckwheat with the activity of IgE binding and pepsin resistance, along with the thermal stability. The identification of natural Fag t 2 (n Fag t 2) confirmed that the Fag t 2 protein belongs to the 2S albumin family, only existing in embryo. Most interesting, we discovered that Fag t 2 had a α-amylase inhibitor domain near the end of C-terminal. The possible activity of α-amylase inhibitor of Fag t 2 will be detected in subsequent studies.
鞑靼荞麦（Fagopyrum tataricum，TB）是一种重要的功能性食品，其蛋白质具有平衡的氨基酸组成，且所含的类黄酮比普通荞麦（Fagopyrum esculentum，CB）更多。荞麦含有高度致敏的过敏原，通过 IgE 介导的反应引发过敏反应。在这项工作中，通过筛选填充期的种子 cDNA 文库，从鞑靼荞麦种子中克隆了全长 cDNA 编码的 Fag t 2。通过固定化金属亲和层析纯化在巴氏毕赤酵母 SMD1168H 中表达的重组 Fag t 2（rFag t 2）。结果表明，Fag t 2 是鞑靼荞麦中的主要过敏原，具有 IgE 结合和胃蛋白酶抗性以及热稳定性。天然 Fag t 2（nFag t 2）的鉴定证实，Fag t 2 蛋白属于 2S 白蛋白家族，仅存在于胚胎中。最有趣的是，我们发现 Fag t 2 在 C 端末端附近有一个α-淀粉酶抑制剂结构域。在随后的研究中将检测 Fag t 2 的α-淀粉酶抑制剂的可能活性。
