ThepotassiumchannelKv1.3isanattractivepharmacologicaltargetforimmunomodulationofTcell-mediatedautoimmunediseases.PotentandselectiveblockersofKv1.3arepotentialtherapeuticsfortreatingthesediseases.HerewedescribethedesignofanewpeptideinhibitorthatispotentandselectiveforKv1.3.Threeresidues(Gly(11),Ile(28),andAsp(33))ofascorpiontoxinBmKTXweresubstitutedbyArg(11),Thr(28),andHis(33),resultinginanewpeptide,namedADWX-1.TheADWX-1peptideblockedKv1.3withpicomolaraffinity(IC(50),1.89pM),showinga100-foldincreaseinactivitycomparedwiththenativeBmKTXtoxin.TheADWX-1alsodisplayedgoodselectivityonKv1.3overrelatedKv1.1andKv1.2channels.Fur
Thermore,alanine-scanningmutagenesiswascarriedouttomapthefunctionalresiduesofADWX-1inblockingKv1.3.Moreover,computationalsimulationwasusedtobuildastructuralmodeloftheADWX-1-Kv1.3complex.ThismodelsuggeststhatallmutatedresiduesarefavorableforboththehighpotencyandselectivityofADWX-1towardKv1.3.WhileArg(11)ofADWX-1interactswithAsp(386)inKv1.3,Thr(28)andHis(33)ofADWX-1locaterightabovetheselectivityfilter-S6linkerofKv1.3.Together,ourdataindicatethatthespecificADWX-1peptidewouldbeaviableleadinthetherapyofTcell-mediatedautoimmunediseases,andthesuccessfuldesignofADWX-1suggeststhatrationaldesignbasedonthestructuralmodelofthepeptide-channelcomplexshouldacceleratethedevelopmentofdiagnosticandtherapeuticagentsforhumanchannelopathies.
SongHan,etal.(2008)StructuralBasisofaPotentPeptideInhibitorDesignedforKv1.3Channel,aTherapeuticTargetofAutoimmuneDisease.JBCPMID:18480054
Thevoltage-gatedKv1.3K(+)channelineffectormemoryTcellsservesasanewtherapeutictargetformultiplesclerosis.Inourpreviousstudies,thenovelpeptideADWX-1wasdesignedandsynthesizedasaspecificKv1.3blocker.However,itisunclearifandhowADWX-1alleviatesexperimentalautoimmuneencephalomyelitis,amodelformultiplesclerosis.Inthisstudy,theadmi
NISTrationofADWX-1significantlyamelioratedtheratexperimentalautoimmuneencephalomyelitismodelbyselectivelyinhibitingCD4(+)CCR7(-)phenotypeeffectormemoryTcellactivation.Incontrast,theKv1.3-specificpeptidehadlittleeffectonCD4(+)CCR7(+)cells,therebylimitingsideeffects.Furthermore,wedeterminedthatADWX-1isinvolvedintheregulationofNF-κBsignalingthroughupstreamproteinkinaseC-θ(PKCθ)intheIL-2pathwayofCD4(+)CCR7(-)cells.TheelevatedexpressionofKv1.3mRNAandproteininactivatedCD4(+)CCR7(-)cellswasreducedbyADWX-1engagement;however,anapparentalterationinCD4(+)CCR7(+)cellswasnotobserved.Moreover,theselectiveregulationoftheKv1.3channelgeneexpressionpatternbyADWX-1providedafurtherandsustainedinhibitionoftheCD4(+)CCR7(-)phenotype,whichdependsontheactivityofKv1.3tomodulateitsactivationsignal.Inaddition,ADWX-1mediatedtheactivationofdifferentiatedTh17cellsthroughtheCCR7(-)phenotype.TheefficacyofADWX-1issupportedbymultiplefunctions,whicharebasedonaKv1.3(high)CD4(+)CCR7(-)Tcellselectivitythroughtwodifferentpathways,includingtheclassicchannelactivity-associatedIL-2pathwayandthenewKv1.3channelgeneexpressionpathway.
ZhiLi,etal.(2012)SelectiveInhibitionofCCR7−EffectorMemoryTCellActivationbyaNovelPeptideTargetingKv1.3ChannelinaRatExperimentalAutoimmuneEncephalomyelitisModel.JBCPMID:22761436
DifferentresiduesinchannelturretdeterminingtheselectivityofADWX-1inhibitorpeptidebetweenKv1.1andKv1.3channels.
ThelowselectivityofKv1peptideinhibitorsforspecificisoformsmakesthempoorcandidatesforthedevelopmentoftheraputics.Usingcombinedapproaches,weshowedthattheKv1turretisthecriticaldeterminantforADWX-1peptideinhibitorselectivityofKv1.3overKv1.1.MutationofKv1.1turretresiduestomatchthesequenceofKv1.3leadtoincreasedinhibitionofKv1.1activity.Thesestudiesmayleadtoimprovementsinpeptideinhibitordrugdevelopment.
YinSJ(2008)DifferentresiduesinchannelturretdeterminingtheselectivityofADWX-1inhibitorpeptidebetweenKv1.1andKv1.3channels.Journalofproteomeresearch PMID:18937510
Smartox生物素ProTx-I电压门控钠通道和T型Cav的阻断剂毒素I（ProTx-1；β-theraphotoxin-Tp1a） 是一种毒素，最初是从Prixopelma pruriens（秘鲁绿色天鹅绒狼蛛）的毒液中分离出来的。此毒素可逆地抑制抗河豚毒素（TTX）的通道 Na v 1.8（IC 50 = 27 nM）和 Na v 1.2，Na v 1.5和Na v 1.7 ，IC 50 值为50至100 nM。此外， ProTx-I 改变了T型Ca v 3.1通道的电压依赖性活动 （IC 50 = 50 nM），而不会影响灭活的电压依赖性。生物素ProTx-I是ProTx-I的生物素标签版本。
