Objective:To analyze antigenic epitopes and express P-glycoprotein.Methods:The target gene was synthesized by the combined use of chemical synthesis and Klenow polymerase extension.The synthesized gene was cloned into expression vector pGEX-2T and expressed

identified and purified it.Results:Antigenic epitopes in extracellular fragment of P-glycoprotein were identified to amino acid residues 82aa~115aa(Ⅰ)、741aa~760aa(Ⅳ)

and 800aa~816aa(Ⅴ).SDS-PAGE analysis indicated that the expressed protein was about 29 kD.Conclusion:High level expression of the target gene fragment was established for preparation of its antibody and biospanning its specific peptide using random phage library

which establishes basis for the targeting treatment of MDR.