ωconotoxinMVIIA (omegaconotoxinMVIIA) hasbeenisolatedfromthevenomoftheconeConusmagus.Omega-conotoxinsactatpresynapticmembranes,theybindandblockvoltage-sensitivecalciumchannels(VSCC). ωconotoxinMVIIA blocks N-typevoltage-gatedcalciumchannels(Cav2.2/CACNA1B). ωconotoxinMVIIA isavailableasanalgesicdrugunderthenamePrialt®.Itblocksacutepaininpatientswhonolongerobtainrelieffromopiatedrugs.Itis100to1.000timesmorepotentthanmorphine.Thistoxinblockscalciumchannelsanddisablesnervesthattransmitpainsignals.
Productcode:08CON001.Categories:Calciumchannels,Highvoltage-gatedCa2+channels.Tags:107452-89-1,Cav2.2,N-type.
AAsequence: Cys1-Lys-Gly-Lys-Gly-Ala-Lys-Cys8-Ser-Arg-Leu-Met-Tyr-Asp-Cys15-Cys16-Thr-Gly-Ser-Cys20-Arg-Ser-Gly-Lys-Cys25-NH2
Disulfidebonds: Cys1-Cys16,Cys8-Cys20 andCys15-Cys25
Length(aa): 25
Formula: C102H172N36O32S7
MolecularWeight: 2639.18Da
Appearance:Whitelyophilizedsolid
Solubility: waterandsalinebuffer
CASnumber: [107452-89-1]Source: Synthetic
Purityrate: >97%
Ziconotide(PRIALT)isaneuroactivepeptideinthefinalstagesofclinicaldevelopmentasanovelnon-opioidtreatmentforseverechronicpain.Itisthesyntheticequivalentofomega-
MVIIA,acomponentofthevenomofthemarinesnail,Conusmagus.Themechanismofactionunderlyingziconotide’stherapeuticprofilederivesfromitspotentandselectiveblockadeofneuronalN-typevoltage-sensitivecalciumchannels(N-VSCCs).DirectblockadeofN-VSCCsinhibitstheactivityofasubsetofneurons,includingpain-sensingprimarynociceptors.Thismechanismofactiondistinguishesziconotidefromallotheranalgesics,includingopioidanalgesics.Infact,ziconotideispotentlyanti-nociceptiveinanimalmodelsofpaininwhichmorphineexhibitspooranti-nociceptiveactivity.Moreover,incontrasttoopiates,tolerancetoziconotideisnotobserved.Clinicalstudiesofziconotideinmorethan2,000patientsrevealimportantcorrelationstoziconotide’snon-clinicalpharmacology.Forexample,ziconotideprovidessignificantpainrelieftoseverechronicpainsuffererswhohavefailedtoobtainrelieffromopiatetherapyandnoevidenceoftolerancetoziconotideisseeninthesepatients.Contingentonregulatoryapproval,ziconotidewillbethefirstinanewclassofneurologicaldrugs:theN-typecalciumchannelblockers,orNCCBs.Itsnovelmechanismofactionasanon-opioidanalgesicsuggestsziconotidehasthepotentialtoplayavaluableroleintreatmentregimensforseverechronicpain.Ifapprovedforclinicaluse,ziconotidewillfurthervalidatetheneuroactivevenompeptidesasasourceofnewandusefulmedicines.
Miljanich,G.P.(2004)Ziconotide:neuronalcalciumchannelblockerfortreatingseverechronicpain,CurrMedChem.PMID:15578997
The
omega-conotoxinsfromthevenomoffish-huntingconesnailsareprobablythemostusefulofpresentlyavailableligandsforneuronalCachannelsfromvertebrates.Twoofthesepeptidetoxins,
omega-conotoxinsMVIIAandMVIIBfromthevenomofConusmagus,werepurified.Theaminoacidsequencesshowsignificantdifferencesfromomega-conotoxinsfromConusgeographus.Totalsynthesisofomega-conotoxinMVIIAwasachieved,and
BIOLOGicallyactiver
ADIolabeledtoxinwasproducedbyiodination.Althoughomega-
conotoxinsfromC.geographus(GVIA)andC.magus(MVIIA)appeartocompeteforthesamesitesinmammalianbrain,inamphibianbrainthehigh-affinitybindingofomega
conotoxinMVIIAhasnarrowerspecificity.Inthissystem,itisdemonstratedthatacombinationoftwoomega-conotoxinscanbeusedforbiochemicallydefiningreceptorsubtypesandsuggestedthatthesecorrespondtosubtypesofneuronalCa2+channels.Olivera,B.M.,etal.(1987)Neuronalcalciumchannelantagonists.Discriminationbetweencalciumchannelsubtypesusingomega-conotoxinfromConusmagusvenom,Biochemistry.PMID:2441741
BowersoxSS,LutherR.Pharmacotherapeuticpotentialofomega-conotoxinMVIIA(SNX-111),anN-typeneuronalcalciumchannelblockerfoundinthevenomofConusmagus. Toxicon. PMID: 9792182
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。