Preparation and Pegylation of TNF-? Derivative / 中国生物工程杂志

The gene of mutated TNF-?D4 gene was amplified by overlap PCR and cloned into the prokaryotic expressive vector pBV220.TNF-?D4 contains two changes:substitutions of Pro8Arg,Ser9Lys,Asp10Arg,Ile157Phe,Leu29Ser,Arg31Val and a deletion of the N terminal four amino acids.The recombinant vector pBV220-TNF-?D4 was transformated into E.coli strain DH5?,and the high expression strain was obtained by screening monoclones.The level of expression was about 45% of total cell protein.After purification,the purity of fusion protein was above 90% by HPLC and relative ability was 8 ?107.TNF-?D4 was modificated by mPEG-ButyrALD。After purification,the purity of mPEG-TNF-?D4 was above 85% and relative ability was 8.6?107.The in vivo systemic toxicity of mPEG-TNF-?D4,which is indicated by LD50,is lower than that of rhTNF-?.These results strongly supported for the further study and exploitation of TNF-antitumor drug.

Expression and Purification of a Novel Influenza Virus Subunit Vaccine / 中国生物工程杂志

The influenza A virus matrix protein2 gene(M2)which deleted transmembrane region was amplified by overlap extending PCR,and the multiepitope gene of hemagglutinin(HA)was PCR amplified with seven continuous synthesized segments by designing primer.The two gene segments were separately cloned into pMD18T vector to sequence analysis and prokarytic expression vector pET28a+ to construct the recombinant plasmid pET28a+M2dHA.The recombinant plasmid was transformed into E.coli BL21(DE3),and the high expression strain was obtained by screening monoclones.The recombinant protein existed as inclusion bodies,which accounted about 45% of the total cellular protein.The inclusion bodies were washed with 1% Triton X100 solution twice,and dissolved in 8 mol/L urea solution.The solution protein was purified by Ni+2 affinity chromatography,and refolded by dilution renaturation,then purified by Q Sepharose FF cation exchange column.The purity of the protein was over 90% by HPLC analysis.The result of Western blot showed it has good antigenicity and specificity.These results strongly supported for the further study of the broadspectrum influenza virus subunit vaccine.

Expression and Purification of Human Parathyroid Hormone Peptide(1-34) in Escherichia coli / 中国生物工程杂志

Human parathyroid hormone peptide1-34(hPTH1-34) was highly expressed in Escherichia coli by inserting the synthesized hPTH1-34 cDNA into pThioHis, the prokaryotic expression vector. The expressed hPTH1-34 was purified by chelating sepharose immobilized metal ion affinity, reverse and filter chromatographic steps. Its purity was verified above 95% by HPLC. The quality was identified by N-terminal sequencing and MALDI-TOF-MS analysis. In vitro analysis showed the adenylate cyclase of ROS 17/2.8 cells was activated by hPTH1-34.