Objective To study the activities of interleukin （IL）-2 and granulocyte-macrophage colony-stimulating factor （GM-CSF） （hlL-2/mGM-CSF）. Methods SOE PCR was used to change the linker of the fusion protein for high...Objective To study the activities of interleukin （IL）-2 and granulocyte-macrophage colony-stimulating factor （GM-CSF） （hlL-2/mGM-CSF）. Methods SOE PCR was used to change the linker of the fusion protein for higher activities. The fusion protein was expressed in Escherichia coli （E. coil） BL21 （DE3） in inclusion body （IB） form. After IB was extracted and clarified, it was denatured and purified by affinity chromatography. The protein was refolded by dilution in a L-arginine refolding buffer and refined by anion chromatography. The protein activity was detected by cytokine-dependent cell proliferation assay. Results The expression of hIL-2/mGM-CSF in E. coli yielded approximately 20 mg protein/L culture and the purity was about 90%. The specific activities of IL-2 and GM-CSF were 5.4×10^6 IU/mg and 7.1×10^6 IU/mg, respectively. Conclusion This research provides important information about the anti-tumor activity of hIL-2/mGM-CSF in vivo, thus facilitating future clinical research on hlL-2/mGM-CSF used in immune therapy.展开更多
Growth and Differentiation Factor-8(GDF-8) is a new member of TGF-β super-family.It has been shown that GDF-8 is specifically expressed in skeleton muscle in mouse and its function is to inhibit the growth of muscle ...Growth and Differentiation Factor-8(GDF-8) is a new member of TGF-β super-family.It has been shown that GDF-8 is specifically expressed in skeleton muscle in mouse and its function is to inhibit the growth of muscle cell,so it is named as Myostatin.Here,we amplified 3′half-length GDF-8 cDNA from chicken skeleton muscle by RT-PCR,and cloned it into the prokaryotic expression vector pTrcHisB,which was then transformed into E.coli Top10 cells.The recombinant 6×His-GDF-8 fusion protein expressed in the Top10 cells was purified by Ni+-Affinity Chromatography for future study.展开更多
A 551-bp hIL-11 gene fragment that includes no nucleotide sequences encoding signalpolypeptide and the initial 8 amino acids of the mature protein was cloned into a high-level expression vectorpEx31B of E.coli.The aut...A 551-bp hIL-11 gene fragment that includes no nucleotide sequences encoding signalpolypeptide and the initial 8 amino acids of the mature protein was cloned into a high-level expression vectorpEx31B of E.coli.The authors identified the recombinant plasmid,designated pEx31-IL11,by restriction endonu-cleases digestion and DNA sequencing.The resulting recombinant plasmids were then used to transform E.colistrain HB101,and expression in the PL promoter system,which is temperature-regulated,was achieved.The ex-pressed fusion protein amounts to 50% of total bacterial proteins.The hIL-11 protein expressed in E.coliwas fused to the N-terminal 99 amino acids of the MS2 polymerase to form the inclusion body.Theserecombinant proteins can be purified to about 80% by extracting inclusion body with urea.OneIL-6-dependent cell line 7 TD1 was used for bioassay.The recombinant hIL-11 protein was preliminarily puri-fied and renatured to a specific activity of 10~5U/mg,even in the presence of an excess of a neutralizing an-ti-IL-6 antibody.展开更多
基金supported by the National Natural Science Foundation of China (30771952)the National Natural Science Foundation of Guangdong Province (07117783)NSFC and the Research Grants Council of Hong Kong Joint Research Scheme (30418003).
文摘Objective To study the activities of interleukin （IL）-2 and granulocyte-macrophage colony-stimulating factor （GM-CSF） （hlL-2/mGM-CSF）. Methods SOE PCR was used to change the linker of the fusion protein for higher activities. The fusion protein was expressed in Escherichia coli （E. coil） BL21 （DE3） in inclusion body （IB） form. After IB was extracted and clarified, it was denatured and purified by affinity chromatography. The protein was refolded by dilution in a L-arginine refolding buffer and refined by anion chromatography. The protein activity was detected by cytokine-dependent cell proliferation assay. Results The expression of hIL-2/mGM-CSF in E. coli yielded approximately 20 mg protein/L culture and the purity was about 90%. The specific activities of IL-2 and GM-CSF were 5.4×10^6 IU/mg and 7.1×10^6 IU/mg, respectively. Conclusion This research provides important information about the anti-tumor activity of hIL-2/mGM-CSF in vivo, thus facilitating future clinical research on hlL-2/mGM-CSF used in immune therapy.
文摘Growth and Differentiation Factor-8(GDF-8) is a new member of TGF-β super-family.It has been shown that GDF-8 is specifically expressed in skeleton muscle in mouse and its function is to inhibit the growth of muscle cell,so it is named as Myostatin.Here,we amplified 3′half-length GDF-8 cDNA from chicken skeleton muscle by RT-PCR,and cloned it into the prokaryotic expression vector pTrcHisB,which was then transformed into E.coli Top10 cells.The recombinant 6×His-GDF-8 fusion protein expressed in the Top10 cells was purified by Ni+-Affinity Chromatography for future study.
文摘A 551-bp hIL-11 gene fragment that includes no nucleotide sequences encoding signalpolypeptide and the initial 8 amino acids of the mature protein was cloned into a high-level expression vectorpEx31B of E.coli.The authors identified the recombinant plasmid,designated pEx31-IL11,by restriction endonu-cleases digestion and DNA sequencing.The resulting recombinant plasmids were then used to transform E.colistrain HB101,and expression in the PL promoter system,which is temperature-regulated,was achieved.The ex-pressed fusion protein amounts to 50% of total bacterial proteins.The hIL-11 protein expressed in E.coliwas fused to the N-terminal 99 amino acids of the MS2 polymerase to form the inclusion body.Theserecombinant proteins can be purified to about 80% by extracting inclusion body with urea.OneIL-6-dependent cell line 7 TD1 was used for bioassay.The recombinant hIL-11 protein was preliminarily puri-fied and renatured to a specific activity of 10~5U/mg,even in the presence of an excess of a neutralizing an-ti-IL-6 antibody.
