Brothers V M, Kuhn I, Paul L S, Gabe J D, Andrews W H, Sias S R, McCaman M T, Dragon E A, Files J G
Codon, South San Francisco, CA 94080.
Mol Biochem Parasitol. 1988 Apr;28(3):235-47. doi: 10.1016/0166-6851(88)90008-4.
An antigenic surface protein of Eimeria tenella sporozoites has been identified that is the target of two neutralizing monoclonal antibodies Ptn 7.2A4/4 and Ptn 9.9D12. The antigen as isolated from the parasite is composed of a 17 kDa polypeptide and a 8 kDa polypeptide linked by a disulfide bridge. De novo synthesis of the antigen does not begin until approximately 16-20 h after the initiation of oocyst sporulation. A cDNA library was constructed using mRNA from sporulated oocysts and a clone encoding the antigen was isolated. The Ta4 gene encodes a single polypeptide of 25 kDa which contains the 17 and 8 kDa polypeptides. The protein has been synthesized in Escherichia coli either directly or as part of a beta-galactosidase fusion protein. The products synthesized in E. coli are single polypeptides and are not cleaved to two polypeptides as is seen in the parasite. The products accumulate in bacteria in an insoluble form which can be solubilized and renatured to an immunoreactive form.
已鉴定出一种柔嫩艾美耳球虫子孢子的抗原性表面蛋白，它是两种中和性单克隆抗体Ptn 7.2A4/4和Ptn 9.9D12的靶标。从寄生虫中分离出的抗原由一条17 kDa多肽和一条8 kDa多肽通过二硫键连接而成。抗原的从头合成直到卵囊孢子化开始后约16 - 20小时才开始。利用孢子化卵囊的mRNA构建了一个cDNA文库，并分离出了一个编码该抗原的克隆。Ta4基因编码一条25 kDa的单一多肽，其中包含17 kDa和8 kDa的多肽。该蛋白已在大肠杆菌中直接合成或作为β-半乳糖苷酶融合蛋白的一部分进行合成。在大肠杆菌中合成的产物是单一多肽，不会像在寄生虫中那样被切割成两条多肽。产物以不溶性形式在细菌中积累，可溶解并复性为免疫反应性形式。
