[Identification of Taenia solium Insulin Receptor TsIR-1316 and Expression of Its Ligand Binding Domain].

Objective: To characterize the structure of insulin receptor of Taenia solium（TsIR-1316） and express its ligand binding domain (LBD).

Methods: Primers for TsIR-1316 were designed according to the genomic data of T. solium, and the TsIR-1316 gene was amplified by PCR. The nucleotide and amino acid sequences of TsIR-1316 were aligned using BLASTN and BLASTP, and the putative signal peptide and structure domains were predicted. The LBD fragment of TsIR-1316 was cloned into the pET-30a（+） vector and expressed. The expressed proteins were purified, separated by SDS-PAGE and analyzed with Western blotting using cysticercus cellulosae-positive serum and TsIR-LBD-immunized rabbit serum.

Results: The open reading frame of TsIR-1316 was 5 196 bp, encoded a protein of 1 732 amino acids which had a typical conserved domain of tyrosine kinase family, was 84% homologous with Echinococcus multilocularis, and had a “V”-shaped tertiary structure. As expected, SDS-PAGE showed that the expressed protein had a band at Mr 59 000. Western blotting showed that the recombinant protein had specific reactions with cysticercus cellulosae positive serum and TsIR-LBD immunized rabbit serum, resulting in a specific band at M(r) 59 000.

Conclusion: The TsIR-1316 gene was successfully cloned and identified. The expressed protein of TsIR-1316 LBD can be recognized by cysticercus cellulosae positive serum, which suggests a good antigenicity of this protein.