Aim: To construct and express a fusion gene of human heptoma peptide (EPVTKAEML) with human heat shock protein 70 (HSP70).
Methods: A cDNA fragment encoding EPVTKAEML was added to 3 terminus of human HSP70 gene by PCR amplification. The PCR products of fusion gene were cloned into pET-28a(+)vector. The recombinant plasmid pET-28a(+)/EPVTKAEML-HSP70 was identified by enzyme digestion analysis and sequencing, and then it was transformed into E.coli BL21(DE3) through IPTG induction to express the target protein bearing His tag.
Results: A fragment of about 2.0 kb was amplified by PCR. Sequence analysis revealed that the sequence of EPVTKAEML was connected successfully to 3 terminus of human HSP70. Enzyme digestion analysis showed the fusion gene was cloned into pET-28a(+). SDS-PAGE showed that a relative molecular mass 72 000 fusion protein was expressed.
Conclusion: The fusion gene of EPVTKAEML-HSP70 has been successfully constructed and expressed in E.coli BL21(DE3).