简介:ToconstructandexpressthefusionproteinStx2B-IntiminC300ofEHEC0157:H7,andtofurtherinvestigateitsimmunoprophyiacticpotential,thegeneofStx2B(stx2b)fromEHEC0157:H7chromosomewasclonedintopMD18-Tvector.Thereafter,theamplifiedgenewasclonedintoprokaryoticexpressionplasmidpET-28a(+)-eaeC300,whichwasconstructedpreviously.TherecombinantpasmidpET-28a(+)-stx2b-eaeC300wastransformedintoE.coliBL21(DE3).Afterinducement,theproteinStx2B-IntiminC300wassuccessfullyexpressedandanalyzedwithsodiumdodecylsulfatepolyacrylamidegelelectrophoresis(SDS-PAGE),WesternblottingandN-terminalaminoacidresidualsequencing.Toevaluateitsimmunoprophyiacticpotential,itwasprimarilypurifiedbyion-exchangechromatographyandinjectedinto30BALB/cmicewithAl(OH)3inthesubscapularregion.Tendaysafterthelastboostervaccination,20micewereattackedwithEHEC0157:H7lysateandtheprotectiveefficacywasobserved.Inthepresentstudy,thegeneofStx2B-IntiminC300wassuccessfullyclonedintopET-28a(+)vector.TheresultsofSDS-PAGEandWesternblottingassayshowedthatthefusionproteinwassuccessfullyexpressedintheinclusionbodyform,accountingfor25%oftotalexpressionproducts,anditsmolecularweightwasabout43kDa.TheresultoftheN-terminalaminoacidresidualsequencingshowedthatitwasidenticaltothatofthemoleculardesigned.Thepuritywasabout75%afterprimarypurification.AnimaltestsrevealedthatthefusionproteinStx2B-IntiminC300haselicitedhightiterofprotectiveantibodyrelatively.TheseresultsdemonstratethatthefusionproteinStx2B-IntiminC300issuccessfullyexpressedinprokaryoticexpressionsystemandshowscertainimmunoprophyiacticpotential.
简介:【摘要】问题链的设计和使用是小学英语教学中发展学生思维能力的重要途径。在小学英语读写课中,基于主题意义的问题链,能够帮助学生深层次理解语篇内涵,感悟语篇主题,促进学生深度学习。本文从聚焦单元主题,巧设问题链;探究单元主题,解决问题链;内化单元主题,迁移问题链三方面阐述了主题意义引领下,如何构建有效的问题链。
简介:8,8′-Dibromo-6,6′,7,7′-tetramethoxy-5,5′-diisopropyl-3,3′-oxydimethylenedinaphtho[2,1-b:2′,1′-d]furan,C32H30Br2O;M.W.=670;triclinic;spacegroupP1;a=8.896(2),b=10.216(1),c=10.423(1)A,α=108.48(1),β=119.36(1),γ=99.26(1);V=723.5A3;Z=1,Dcal.=1.479g.cm-3.MoKα=28.11cm-1,F(000)=326,T=293K.Thestructurewassolvedbydirectmethodandfull-matrixleast-squaresrefinementconvergedatR=0.034for2377observedreflections.Theoxygenatominseven-memberedringexistsinadisorderedarrangement.Bothbisnaphthaleneandoxygen-containingfive-memberedringhaveplanarconformationswithdihedralangle6°,showingmarkedaromaticfeature.