Optimization of Expression by Response Surface Methodology and Purification of Recombinant Human Cardiac Troponin-I(cTnI) in Escherichia coli / 中国生物工程杂志

ABSTRACT

To optimize the growth condition for the established gene engineer bacteria express cardiac troponin-I(cTnI) and to obtain purified cTnI as an antigen to produce clinical assay kits used in acute myocardial injury(AMI) diagnosis.Plackett Burman Design(PBD) was applied to select the factors which effect the expression of cTnI in Escherichial coli(E.coli) mostly.Induction time,pH and KCl were proved influenced expression of cTnI notably.Afterward,Response Surface Methodology(RSM) as second step to optimize the selected three factors,an equation was deduced to predict the percent of cTnI.In the most optimized condition,the percent of cTnI can reach to 26% of total cell protein.The procedures of purification included ammonium sulfate deposition and DEAE Cellulose ion exchange chromatography.SDS-PAGE shows that purified cTnI contain one band.cTnI could be used to immune animals as an antigen to produce monoclonal antibodies with high affinity and specificity.It maybe as calibrators to harmony the difference assays of cTnI measurement in clinical.