Virus-binding activity of the truncated C subunit of porcine aminopeptidase N expressed in Escherichia coli

Sun, Dongbo; Shi, Hongyan; Chen, Jianfei; Guo, Donghua; Liu, Quan; He, Xianjing; Bao, Jun; Wang, Yunfeng; Qiu, Huaji; Feng, Li

Seven overlapping truncated forms of the C subunit of porcine aminopeptidase N (pAPN-C) were expressed in Escherichia coli. By western blotting and ELISA test, all recombinant proteins were recognized by the antibody against native porcine aminopeptidase N. Recombinant proteins, rpAPN-C2 (aa 623–722) and rpAPN-C3 (aa 673–772), had the highest binding activity with swine transmissible gastroenteritis virus among the truncated pAPN-C recombinant proteins. The overlapping region (aa 673–722) between rpAPN-C2 and rpAPN-C3 is indicated to play a key role in viral binding. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10529-011-0795-1) contains supplementary material, which is available to authorized users.