Prokaryotic soluble expression of protein D of Haemophilus influenzae type b

Objective To express the recombinant D protein in prokaryotic expression system solubly and make preparation for producing D-carrier conjugate vaccine next step.Methods The hpd gene fragment removed of signal peptide from genomic DNA of Hib CMCC was inserted into pET43.1a.The recombinant plasmid was transformed to competent E.coli BL21 (DE3) for expression under induction of IPTG.The expressed recombination protein was precipitated with ammonium sulfate,purified by DEAE anion exchange column chromatography and identified for reactogenicity by Western Blot.Results The expressed recombination protein,in a soluble form,constained about 50％ of total somatic protein and showed specific reaction with the HIB antisera after preliminary purification.Conclusion The D protein recombined expression plasmid was constructed successfully and expressed D protein in prokaryotic cells in a solube form. Key words: Proteins; Expressed sequence tags; Haemophilus influenzae type b