Prokaryotic expression,purification and identification of truncated BAP31/GST fusion protein

In this study,we aimed to construct a expression plasmid for△BAP31 gene and identify the recombinant protein expression.Firstly,the△BAP31 coding sequence was amplified by polymerase chain reaction(PCR) method and subcloned into pGEX-4T1vector.After the target gene was sequenced,the plasmid was transformed into E coil DH5α and induced with IPTG to express fusion protein △BAP31/GST which was then proved by SDS-PAGE and Western blot.SDS-PAGE analysis showed that a novel protein with the expected molecular mass about 40 000 was expressed with the inducement of IPTG.The fusion protein was existed mostly in the form of soluble protein,and grayscale scanning showed that the expressed △BAP31/GST fusion protein was accounted for 70.6% of the total bacterium protein.The purity of the fusion protein reached 94.5% after purification by High-Affinity GST Resin.Then western blot confirmed the recombinant protein was △BAP31/GST fusion protein.In our study,high purification △BAP31/GST fusion protein is obtained through the E.coil expression system.