Abstract:

Abstract:Objective
To establish E.coli strain and express human fibroblast growth factor 21(FGF21),and   provide experimental foundation for development of  new drugs for treatment of  type 2 diabetes.Methods Human FGF21 gene fragments were obtanined by PCR.After the FGF21 was fused with SUMO (small ubiquitin-related modifier) by PCR,the fused gene was expressed in E.coli BL21(Rosetta).By inducing high levels of expression with IPTG,the soluble proteins were obtanined.The fused protein was purified by DEAE Sepharose and Ni-NTA affinity chromatography.Once cleaved from SUMO,the purity of human FGF21 by SDS-PAGE was shown to be higher than 95%.Results  Acquired gene fragments of hFGF21 were identified by digestion and DNA sequencing with the human FGF21 reported in GenBank (Accession no.NM019113 ).The recombinant vector of pET20b-SUMO-FGF21 was constructed successfully.SDS-PAGE result proved that SUMO-FGF21 fusion protein with a relative molecular mass of about 19 401 was expressed.Western blotting result showed that the expressed products had specific reaction with anti-human FGF21 polyclonal antibody.Conclusion The engineering E.coli strain expressing human FGF21 fusion protein is successfully established and the purified protein is obtained.

Key words: fibroblast growth , factor 21;pET-20b;small ubiquitin-related modifier proteins