Effects Of Anti-tumor Peptide 19 On Ion Channels Of Cell Membrane And Preliminary Study On Heart Safety

Tumstatin as autoantigen of lung-kidney syndrome,in the 80 s as collagen IV α3 chain of collagen area was found.Rencent researchs of related peptide of tumstatin focus on antitumor activity,however,anti-tumor peptide action mechanism and application security have become a hot spot in recent years.With the continuous development of patch clamp technique progress has evolved a variety of recording models suitable for the studies of different needs,and became an important technique in modern electrophysiology and hymenology.Application of patch clamp can profoundly investigate in ion channel,Ion channel modulation mechanism and cell membrane selectivity penetration.In this study,recombinant vector pet32a-19 peptide used to induce aniti-tumor peptide 19 in E.coli,it was extracted,purified and refolded.Dissolve the anti-tumor 19 peptide with insolution and make the concentration of 50μg/ml,100μg/ml and 200μg/ml,respectively.The perforated patch mode result showed that the anti-tumor 19 peptide which density are between50μg/ml to 200μg/ml could damage effect on the membrane of human hepatoma cells(SMMC-7721).which is stronger depended on the concentration of anti-tumor 19 peptide,check the bore used method of electrophysiology after giga seal during fifteen minutes after.In the same experimental methods and conditions,but 200μg/ml anti-tumor 19 peptide didn’t have effect on ventricular myocytes of rabbits.The results of whole cell patch recording mode shown the concentration of 200μg/ml anti-tumor 19 peptide could restrain the delayed rectifier kalium current of SMMC-7721,the current density descended from 87.27±4.49 p A/p F to 58.39±12.88 p A/p F,the peak current decline33.09 percents(n=5,P < 0.05).However,anti-tumor 19 peptide didn’t have significant inhibitory effect on rabbit ventricular myocytes,and the peak current decline only 0.01%(n=5,P>0.05).The concentration of 200μg/ml anti-tumor 19 peptide also restained the solium current and make the current density decreased from 84.68±4.63 p A/p F to 52.18±2.92 p A/p F,the peak current decline 38.38 percents(n=5,p<0.05).Survey the voltage depend on solium and kalium ion channels during anti-tumor 19 peptide effect on SMMC-7721 reflect the standed of Electrophysical.The above results indicated that anti-tumor 19 can anti-tumor and had no damage effect on normal cells.The whole cell patch recording mode was further used to study the effect of anti-tumor 19 peptide on hERG potassium channel,and the result showed that anti-tumor 19 peptide had no obvious inhibitory effect on hERG potassium channel in the range of 25μg/ml to 400μg/ml at different concentrations.Among them,the anti-tumor 19 at the highest concentration of400μg/ml reduced the hERG current only by 5.6 percents(n=5,P >0.05)...