ABSTRACT
<p><b>OBJECTIVE</b>To express SPAG4L, a novel human testis gene in E. coli and purify it's fusion protein.</p><p><b>METHODS</b>The fragment encoding SPAG4L126-379 was amplified by RT-PCR and the PCR products were cloned into PUCm-T vectors. After digestion by EcoR I and Hind III, the fragment was subcloned into PQE-30, a prokaryotic expression vector with 6×His tag. The recombinant plasmid PQE-30-SPAG4L was sequenced and transformed into E.coli M15. The expression of his-tagged fusion protein was induced by IPTG. The fusion protein was identified by Western blotting and purified using Ni-NTA magnetic agarose beads.</p><p><b>RESULTS</b>The recombinant plasmid PQE-30-SPAG4L was constructed successfully and expressed in E.coli M15. The fusion protein SPAG4Lwith 6×his-tag was confirmed by Western blotting. The micro-scale purification system of 6×His-tagged SPAG4Lprotein was established and purified fusion protein was obtained.</p><p><b>CONCLUSION</b>The recombinant plasmid PQE-30-SPAG4L can be expressed in vitro and used for studying the biological function of SPAG4L in spermatogenesis.</p>