关键词: 肿瘤抑素；亲和层析；抗肿瘤活性；半数抑制浓度

Abstract:

Abstract:Objective
To extract and purify anti-tumor peptide of tumor chalone T42 peptide from gene engineering bacteria pTYB2-T42 and  identify its biological activity,and  provide the experimental basis for the research of its function mechanism and the clinical treatment of tumors.Methods The pTYB2-T42 in E.coli was cultivated,and fusion protein was produced by IPTG,T42 peptide was extracted by the method of affinity chromatograph,DTT was removed by molecular sieve G15 and then T42 peptide was identified by Trincine SDS-PAGE.The influence of T42 peptide on the cell activity was detected by MTT.The apoptosis of T42 peptide was detected by AO/EB.Results  The recombinant expression vector coding tumstatin T42 peptide was correct in size,its relative molecular mass was about 5 000.The result of MTT showed that the proliferation of growth of Hepg2 cells was inhibited by T42 peptide,and the survival rate of Hepg2 cells was decreased with the increase of T42 peptide dose,and IC₅₀ was 30 mmol•L^-1.The result of AO/EB indicated that the Hepg2 cells appeared typical characteristics of apoptosis after treated with T42 peptide for 24 h.Conclusion  T42 peptide evidently inhibit the proliferation of growth of  Hepg2 cells  in a dose-dependent manner,and it can promote the apoptosis of Hepg2 cells.

Key words:  tumstatin；affinity chromatography；antitumor activity； inhibitory concentration 50