Abstract: To construct the heavy chain of SLA-2 conjugated with the BirA substrate peptide(BSP)and express the recombinant genes in pET-28a(+)for Yantai Black Pig(YTH), a pair of primers to express the recombinant SLA-2-YTH-BSP was designed and the recombinant SLA-2-YTH-BSP was amplified by PCR followed by sub-cloning the gene into pMD19-T Simple Vector. After identification by cleavage with Nde I and Xho I, the SLA-2-YTH-BSP was ligated to pET-28a(+)and the recombinant plasmids was transformed into BL21 (Rosseta)to be induced to express followed by analysis of the expressing products by SDS-PAGE. The expressed interest of protein was purified by Ni-NTA column and detected by SDS-PAGE. The PCR results showed that the length of nucleotides of SLA-2-YTH-BSP was about 900 bp which was consistent with the calculated value. Then, the SLA-2-YTH-BSP with 876 bp was successfully inserted into the pMD-19-T Simple Vector identified by cleavage with Nde I and Xho I, and then the genes were inserted into pET-28a(+)and transformed into Escherichia coli BL21(Rosseta). After induction, SLA-2-YTH-BSP was successfully expressed with the interest of protein about 32.4 kD. After purification,the purity of the interest of the inclusion protein reached to 90%. It was concluded that the recombinant expressing system containing SLA-2 conjugated with BSP in pET-28a(+)was successfully constructed and the research would pave the base to construct tetramer in SLA class I.

Key words: Yantai black pig SLA-2, Heavy chain gene, BirA substrate peptide, Purification