Kimoto Masumi, Suzuki Makiko, Komiyama Nobuko, Kunimoto Ayumi, Yamashita Hiromi, Hiemori Miki, Takahashi Kyoko, Tsuji Hideaki
Department of Nutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University.
Biosci Biotechnol Biochem. 2009 Jan;73(1):85-92. doi: 10.1271/bbb.80485. Epub 2009 Jan 7.
Tri a Bd 27K is the predominant allergen in wheat. In the present study, this allergen was purified to homogeneity from wheat flour. The N-terminal amino acid sequences of the purified allergen and the peptides obtained by its digestion, with trypsin were determined, and the allergen was shown to be a glycoprotein with an Asn-linked sugar moiety containing fucose residues. A cDNA encoding the allergen was obtained by polymerase chain reaction (PCR). The cDNA codes for a protein of 203 amino acid residues, with a molecular mass of 22,803 Da, that has two tentative sites glycosylated at Asn residues. Homology analysis suggested that the allergen might belong to a family of gamma-interferon-inducible thiol reductases. The cDNA was expressed as a fusion protein with glutathione S-transferase in Escherichia coli. However, unlike the allergen purified from wheat, recombinant Tri a Bd 27K was not immunoblotted with IgE antibodies in the serum of a wheat-sensitive patient.
Tri a Bd 27K是小麦中的主要过敏原。在本研究中，该过敏原从小麦粉中纯化至同质。测定了纯化过敏原及其经胰蛋白酶消化得到的肽段的N端氨基酸序列，结果表明该过敏原是一种糖蛋白，带有含岩藻糖残基的N-连接糖部分。通过聚合酶链反应（PCR）获得了编码该过敏原的cDNA。该cDNA编码一个由203个氨基酸残基组成的蛋白质，分子量为22,803 Da，在Asn残基处有两个潜在的糖基化位点。同源性分析表明，该过敏原可能属于γ-干扰素诱导的硫醇还原酶家族。该cDNA在大肠杆菌中表达为与谷胱甘肽S-转移酶的融合蛋白。然而，与从小麦中纯化的过敏原不同，重组Tri a Bd 27K不能被小麦敏感患者血清中的IgE抗体免疫印迹。
