Tocloneandconstructtherecombinantplasmidcontainingthemajoroutermembraneprotein(MOMP)geneofChlamydiatrachomatis(C.trachomatis)andtoexpressthefusionproteininE.coliBL21,theMOMPgenewasamphfiedbypolymerasechainreaction(PCR)fromgenomeofC.trachomatisserovarD.ThefragmentwasclonedintotheprokaryoticexpressionvectorpET-22b(+)afterdigestionwithBamHⅠandNotⅠandtransformedintoE.coliXL1-Blue.RecombinantswereselectedbyenzymedigestionandsequencingandtherecombinantplasmidwithMOMPgenewasthentransformedintoE.coliBL21withIPTGtoexpressthetargetgene.TheexpressionrecombinantproteinswerepurifiedbyNi-NTAaffinitychromatography,andidentifiedbySDS-PAGEandWesternblot.Itwasfoundthata1.2kbMOMPgenewasisolated.TheDNAsequenceofMOMPwasfoundtobejustthesameasthesequencepublishedbyGenBank.ArecombinantplasmidcontainingMOMPgenewasconstructedtoexpressthefusionproteinsinE.coli.SDS-PAGEanalysisshowedthattherelativemolecularweightoftherecombinantproteinwasabout47kDathatwasconsistentwiththetheoreticalpredictedvalue,andthespecificityoftheexpressedproteinwasconformedbyWesternblot.ItconcludedthattheMOMPgenecouldbeexpressedintheprokaryoticsystem,bywhichitprovidedthefoundationforthefuturestudiesonthebiologicalactivitiesofC.trachomatisandforthedevelopmentofvaccineagainstthispathogen.
