*2009-07-25**(1982-),,,。(auto-induction),80CoffeyTGF-α[1]。。Studier,。,,YuAPRIL[2]、Tustx2[3]。1,。4000,[4]。20,,。20[5],。20,,。,(),。;,mRNA,。,。lac、trp、tac、λPL。pUCpBS,DNAlac。2T7T7。T7,;37℃13min,T7250T7***100044。。Q591·2ACN11-5340/N(2009)03-0010-06()JOURNALOFBEIJINGINSTTTUTEOFEDUCATION(NATURALSCIENCEEDITION)4320099Vol.4No.3Sep.200910。T7E.coliRNA,E.coliRNAT7RNA;T71RNA[6]。T7RNA。T7:T7RNAT7,;T7mRNA;T7mRNA。T7,BL21(DE3),T7RNA,lacUV5,(lactoseoperon)(1)。T7,T7RNA[6,7]。(inducer),lacI()lacO,lacT7RNA,,。(IPTG),,lacOT7RNA;T7RNAT7DNA。mRNA(rbs、Met),。T7,T7RNA,。,,。laclacOT7,T7lac[8]。NovagenpET,T7lac。,laclacO,,T7RNA,T7RNAT7。T7lac。lac,;,lacUV5T7,[9]。,T7lacT7。3T7IPTGT7。,。IPTG,。lacmRNA(backgroundlevelconstitutivesynthesis)[10],T7lac,,。,IPTG,。、[11-12]。lacmRNA,。LB,(tryptone),。(casein),,1(Hartwell,2008):T711();。。,。。(cataboliterepression)[10],,lac(2)。。4,Studier。,,。lacYlacZ(lactosepermease)β-(β-galactosidase),T7;(gal)。Studier,、,,。15N13C,。,———MDG[11](1)。,,。,———ZYM-0.8G(2)。,0.8%,。StudierMDAG[11]ZYM-0.8G,17,2。,MDAG。,———ZYM-5052[11](3)。,。50525‰,0.5‰2‰。,,2。,,。1MDG(10ml)9.15mlH2O25mMNa2HPO420μl1MMgSO425mMKH2PO42μl1000×50mMNH4Cl125μl40%5mMNa2SO4500μl5%2mMMgSO4200μl50×M0.2×0.5%0.25%12。Studier,[11];,lac,。,。,15N———N-5052[11](4)。15N,15N。,,ZYM-5052。,NH4+。,13C———C-750501[11](4)。:、。,13C。0.01%;,。,13C。,。:,50×M,,17.75gNa2HPO4、17.0gKH2PO4、13.4gNH4Cl、3.55gNa2SO4,100ml。pH6.7。,。。,40%(w/v)。,,30min。,。2ZYM-0.8G(10ml)9.58mlZY1%N-Z-amineAS20μl1MMgSO40.5%2μl1000×25mMNa2HPO4200μl40%25mMKH2PO4200μl50×M50mMNH4Cl5mMNa2SO42mMMgSO40.2×0.8%3ZYM-5052(10ml)9.58mlZY1%N-Z-amineAS20μl1MMgSO40.5%2μl1000×25mMNa2HPO4200μl50×505225mMKH2PO4200μl50×M50mMNH4Cl5mMNa2SO42mMMgSO40.2×0.05%0.5%0.2%α-:T713(),50×5052,100ml25g、2.5g、α-10g(),,40%。(2.5%,)。,1000×,100ml0.1MFeCl350ml、1MCaCl22ml、1MMnCl21ml、1MZnSO41ml、0.2MCoCl21ml、0.1MCuCl22ml、0.2MNiCl21ml、0.1MNa2MoO42ml、0.1MNa2SeO32ml、0.1MH3BO32ml,。,。FeCl3,;,。5,。ZY,StudierN-Z-amineAS(sigmaN4517),N-Z-amineAS。Mg2+;Kana,Kana,Kana100μg/ml。,:,0.2,、MgSO450×M,50×5052。,。,,。,Studierbaffledflask,(),,。,。,300rpm,,。Studier,37℃,37℃[8],。,A600,。,:(1)(T7)BL21(DE3),1%LB(),37℃。(2),ZYM-0.8G(,Kana),37℃6-8h,。(3),ZYM-0.8G1∶1000ZYM-5052(4N-5052C-750501N-5052C-75050150mMNa2HPO450mMNa2HPO450mMKH2PO450mMKH2PO450mM15NH4Cl50mMNH4Cl5mMNa2SO45mMNa2SO42mMMgSO42mMMgSO40.2×0.2×0.5%0.75%13C-0.05%0.05%0.2%α-0.01%α-14,Kana),15。(4)37℃37℃,。(5),、。:,,;,IPTG;,;,NMR13C15N,(M9)。NMR,。:[1]R.Coffey,R.Derynck,J.Wilcox,T.Bringman,A.Goustin,H.Moses,M.Pittelkow.Productionandauto-inductionoftransforminggrowthfactor-alphainhumankeratinocytes[J].Nature,1987,328:817-820.[2]S.Yu,Y.Wang,Y.Liu,W.Mo,H.Song,M.Yu.ExpressionandpurificationofAPRILbyauto-induction[J].ProteinExprPurif,2009,Inpress.[3]W.Tu,K.Cai,X.Gao,L.Xiao,R.Chen,J.Shi,H.Liu,X.Hou,Q.Wang,H.Wang.ImprovedproductionofholotoxinStx2withbiologicalactivitiesbyusingasingle-promotervectorandanauto-inductionexpressionsystem[J].ProteinExprPurif,2009,Inpress.[4]T.A.Brown.GenecloningandDNAanalysis:anintroduction(5edition)[M].Oxford:Wiley-Blackwell,2006.[5]F.Baneyx.RecombinantproteinexpressioninEscheichiacoli.CurrentOpinioninBiotechnology.1999,10:411-421.[6]F.W.Studier,B.A.Moffatt,UseofbacteriophageT7RNApolymerasetodirectselectivehigh-levelexpressionofclonedgenes[J].J.Mol.Biol,1986,189:113-130.[7]F.W.Studier,A.H.Rosenberg,J.J.Dunn,J.W.Dubendorff,UseofT7RNApolymerasetodirectexpressionofclonedgenes[J].MethodsEnzymol,1990,185:60-89.[8]J.W.Dubendorff,F.W.Studier.ControllingbasalexpressioninaninducibleT7expressionsystembyblockingthetargetT7promoterwithlacrepressor[J].J.Mol.Biol,1991,219:45-59.[9]P.J.Lopez,J.Guillerez,R.Sousa,M.Dreyfus.OnthemechanismofinhibitionofphageT7RNApolymerasebylacrepressor[J].J.Mol.Biol,1998,276:861-875.[10]R.F.Weaver.Molecularbiology(4edition)[M].Boston:McGraw-HillCompanies,2008.[11]F.W.Studier.Proteinproductionbyauto-inductioninhigh-densityshakingcultures[J].ProteinExpressionandPurification,2005,41:207-234.[12]J.Meerman,G.Georgiou.ConstructionandcharacterizationofasetofE.colistrainsdeficentinallknownlociaffectingtheproteolyticstabilityofsecretedrecombinantproteins[J].Biotechnology,1994,12:1107-1110.T7ExpressionSystemandProteinProductionbyAuto-inductionStrategyFengShan(FacultyofEducationforTeachersofScienceandMath,BeijingInstituteofEducation,Beijing100044,China)Abstract:Averypopularmethodofensuringtightcontrol,aswellashigh-levelinducedexpression,istoplacethegenetobeexpressedinaplasmidundercontrolofaT7phagepromoter.However,there’ssurelysomedisadvantagesintheinducibleexpressionsystemswhichwerecurrentlyused.Studierandhiscoworkersinventedtheconceptofauto-induction,usingtheirauto-inducingmediainhigh-densityshakingculturesmightgetproteinsbetterbothinqualityandquantity.Keywords:auto-induction;expressionvectors;T7promoter;media:T715