N-typecalciumchannelsplayimportantrolesinthecontrolofneurotransmissionreleaseandtransmissionofpainsignalstothecentralnervoussystem.Theirselectiveinhibitorsarebelievedtobepotentialdrugsfortreatingchronicpain.Inthisstudy,anovelneurotoxinnamedHuwentoxin-XVI(HWTX-XVI)specificforN-typecalciumchannelswaspurifiedandcharacterizedfromthevenomofChinesetarantulaOrnithoctonushuwena.HWTX-XVIiscomposedof39aminoacidresiduesincludingsixcysteinesthatconstitutethreedisulfidebridges.HWTX-XVIcouldalmostcompletelyblockthetwitchresponseofratvasdeferenstolow-frequencyelectricalstimulation.ElectrophysiologicalassayindicatedthatHWTX-XVIspecificallyinhibitedN-typecalciumchannelsinratdorsalrootganglioncells(IC50∼60 nM).TheinhibitoryeffectofHWTX-XVIonN-typecalciumchannelcurrentswasdose-dependentandsimilartothatofCTx-GVIAandCTx-MVIIA.However,thethreepeptidesexhibitedmarkedlydifferentdegreesofreversibilityafterblock.Thetoxinhadnoeffectonvoltage-gatedT-typecalciumchannels,potassiumchannelsorsodiumchannels.IntraperitonealinjectionofthetoxinHWTX-XVItoratselicitedsignificantanalgesicresponsestoformalin-inducedinflammationpain.Toxintreatmentalsochangedwithdrawallatencyinhotplatetests.Intriguingly,wefoundthatintramuscularinjectionofthetoxinreducedmechanicalallodyniainducedbyincisionalinjuryinVonFreytest.Thus,ourfindingssuggestthattheanalgesicpotencyofHWTX-XVIanditsgreaterreversibilitycouldcontributetothedesignofanovelpotentialanalgesicagentwithhighpotencyandlowsideeffects

DengM.,etal.(2014)Huwentoxin-XVI,ananalgesic,highlyreversiblemammalianN-typecalciumchannelantagonistfromChinesetarantulaOrnithoctonushuwena.Neuropharmacol. 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。