Abstract: The cDNA sequence of full-length A1a acidic peptide from glycinin was synthesized and inserted into the prokaryotic expression vector pET-30a. The A1a fusion protein was expressed in Escherichia coli BL21 (DE3) with the induction of IPTG. The highest expression level was observed after IPTG induction for 5 h. The recombinant protein was purified by His-tag affinity chromatography. The purity of Ala fusion protein was 90% and its molecular weight was approximately 38 kD. Western blotting analysis revealed that the recombinant protein had immunological activity because it could react with the serum of soybean meal allergic piglet. These results are helpful to develop an immunoassay for detecting A1a acidic peptide and exploring its mechanisms.

Key words: glycinin, A1a acidic peptide, prokaryotic expression, Western blotting