Protein Disulfide-Isomerase (PDI, Enzyme Code 5.3.4.1) accelerates the exchange reactions between disulfide bonds in proteins in the presence of appropriate oxidizing or reducing reagents. It is especially useful when working with recombinant proteins that sometimes lack the tertiary structure of native proteins and are therefore not functional.
ebiomall.com
>
>
>
>
>
>
>
>
>
>
>
>
本人目前需从电鳗放电器官中提取乙酰胆碱受体蛋白,提纯需要的步骤和电鳗器官都可以提供,有没有提供外包提纯服务的公司或者实验室。
NaturalProteinStopsDeadlyHumanBrainCancerInMice
ScientistsfromJohnsHopkinsandfromtheUniversityofMilanhaveeffectivelyproventhattheycaninhibitlethalhumanbraincancersinmiceusingaproteinthatselectivelyinducespositivechangesintheactivityofcellsthatbehavelikecancerstemcells.ThereportispublishedinNature.
Themostcommontypeofbraincancer-glioblastoma-ismarkedbythepresenceofthesestem-cell-likebraincells,which,insteadoftriggeringthereplacementofdamagedcells,formcancertissue.Stemcells,unlikeallothercellsinthebody,arecapableofformingalmostanykindofcellwhentheright"signals"triggertheirdevelopment.
Fortheirtreatmentexperiment,theresearchersreliedonaclassofproteins,bonemorphogenicproteins,thatcauseneuralstem-cell-likeclusterstolosetheirstemcellproperties,whichinturnstopstheirABIlitytodivide.
Firsttheypretreatedhumanglioblastomacellswithbonemorphogenicprotein4(BMP4),theninjectedthesetreatedcellsintomousebrains.Inmiceinjectedwithcellsthatwerenotpretreated,large,invasivecancersgrew.InthemicewithBMP4-treatedcells,nocancersgrewatall.Threetofourmonthsafterinjection,allmicethatgotuntreatedcellsdied,andnearlyallmicewithBMP4-treatedcellswerealive.
Next,thescientistsdeliveredslow-releaseBMP4-containing"beads"directlyintomousebrainswithimplantedglioblastomacells.Micethatgotemptybeadsdevelopedlargemalignanttumorsanddied.MicewithBMP4beadssurvivedmuchlonger,and80percentsurvivedfourmonthsaftercancercellimplants.
"OurideaistotreatpatientswithBMP4orsomethinglikeitrightaftersurgerytoremoveglioblastomainhopesofpreventingtheregrowthofthecancerandimprovingsurvivaltime,"saysAlessandroOlivi,M.D.,directoroftheDivisionofNeurosurgicalOncologyatHopkinsandacontributortothestudy.
OlivisaysclinicalstudiesusingBMP4couldbeginwithinayearand,ifsuccessful,drugtherapiescouldbeavailabletothepublicwithinthreetofouryears.
"ThiswasproofoftheideathatBMPscouldstopglioblastomabydepletingthestem-cell-likepopulationthatfeedsit,"saysHenryBrem,M.D.,chairmanoftheDepartmentofNeurosurgeryatHopkinsandacollaboratorinthestudy."Thisopensexcitingdoorstofutureresearchintotreatmentsandtherapiesforsuchadevastatingdisease."

