ABSTRACT
Objective: To chine and express the recombinant human endothelial monocyte-activating polypeptide-Ⅱ(EMAP-Ⅱ)and identify its anti-tumor biological activities.Methods: EMAP-Ⅱ_(147-312)was expressed by the expression vector pMAL-p2x and E.coli BL-21 and the product was purified.The production of tissue factor(TF)in human umbili- cal vein endothelial cell ECV-304 mediated by the recombinant EMAP-Ⅱwas determined by chemiluminescence sub- strate.The promoting effect of recombinant EMAP-Ⅱon TNF?-induced ECV-304 cell.Apoptosis was determined by flow cytometry.Its inhibitory effect on human pancreaic cancer cell SW1990 proliferation was determined by MTT method. Results:DNA sequencing verified that EMAP-Ⅱwas correctly cloned.The molecular mass of the protein identified by SDS-PAGE was consistent with the theoretic value.The productivity of recombinant EMAP-Ⅱwas 500?g per 1 g bacteria (wet mass).The purified product induced expression of tissue factor(TF)in ECV-304 cells;it also enhanced the sensi- tivity of ECV-304 cells to the apoptotic effect of TNF?([16.6?2.5]% vs[25.6?2.3]%,P
ABSTRACT
Objective:To express Tumstatin_(183-230)-TRAIL fusion protein and to observe its biological functions.Methods: SOE-ing PCR was employed to amplify the recombinant sequence of Tumstatin_(183-230)and TNF-related apoptosis-inducing ligand (TRAIL_(114-281)).An expression vector pMAL-Tu-T was constructed by inserting Tu-T sequence into pMAL-c_2;the vector was used to transfect E.coli BL21(DE3)and expression of MBP-Tu-T fusion protein was induced by IPTG.Amylose Resin columns were employed to purify the fusion protein.The biological functions of MBP-Tu-T protein was examined by inhibitory test of endothelial cell proliferation,standard tumor cell cytotoxic assay,in vitro tube formation inhibition,and electron microscopic observation(apoptosis).Results:The expression rate of MBP-Tu-T fusion protein in E.coli was about 20%. Purified recombinant protein obviously inhibited endothelial cell proliferation(IC_(50)12.5?g/ml),induced apoptosis of pancreatic cancer cells,and inhibited tube formation.Conclusion:Constructed MBP-Tu-T fusion protein is bifunctional,which lays a solid foundation for further investigation of antitumor effect of Tumstatin_(183-230)-TRAIL in vivo.