Arruda L K, Vailes L D, Platts-Mills T A, Hayden M L, Chapman M D
Asthma and Allergic Diseases Center, University of Virginia, Charlottesville, Virginia 22908, USA.
J Biol Chem. 1997 Aug 15;272(33):20907-12. doi: 10.1074/jbc.272.33.20907.
We report that a major 23-kDa allergen from German cockroach (Blattella germanica) is a glutathione S-transferase (EC 2.5.1.18; GST). Natural B. germanica GST, purified from cockroach body extracts by glutathione affinity chromatography, and recombinant protein expressed in Escherichia coli using the pET21a vector, showed excellent IgE antibody binding activity. B. germanica GST caused positive immediate skin tests in cockroach-allergic patients using as little as 3 pg of recombinant protein. The NH2-terminal sequence of the natural protein and the deduced amino acid sequence from cDNA were identical except for one substitution (Phe9 --> Cys). Assignment of this protein to the GST superfamily was based on binding to glutathione and sequence identity (42-51%) to the GST-2 subfamily from insects, including Anopheles gambiae and Drosophila melanogaster. B. germanica GST contained 18 of the 26 invariable residues identified in mammalian GST by x-ray crystallography and exhibited enzymic activity against a GST substrate. Our results show that cockroach GST causes IgE antibody responses and is associated with asthma. The data strongly support the view that the immune response to GST plays an important role in allergic diseases.
我们报告称，德国小蠊（Blattella germanica）的一种主要23 kDa变应原是谷胱甘肽S-转移酶（EC 2.5.1.18；GST）。通过谷胱甘肽亲和层析从蟑螂身体提取物中纯化得到的天然德国小蠊GST，以及使用pET21a载体在大肠杆菌中表达的重组蛋白，均显示出优异的IgE抗体结合活性。德国小蠊GST在蟑螂过敏患者中引发了阳性速发型皮肤试验，所用重组蛋白低至3 pg。天然蛋白的NH2末端序列与cDNA推导的氨基酸序列除一处替换（Phe9 --> Cys）外完全相同。该蛋白归属于GST超家族是基于其与谷胱甘肽的结合以及与包括冈比亚按蚊和黑腹果蝇在内的昆虫GST-2亚家族的序列同一性（42 - 51%）。德国小蠊GST含有通过X射线晶体学在哺乳动物GST中鉴定出的26个不变残基中的18个，并对一种GST底物表现出酶活性。我们的结果表明，蟑螂GST引发IgE抗体反应并与哮喘相关。这些数据有力地支持了对GST的免疫反应在过敏性疾病中起重要作用这一观点。
