ωconotoxinMVIIA (omegaconotoxinMVIIA) hasbeenisolatedfromthevenomoftheconeConusmagus.Omega-conotoxinsactatpresynapticmembranes,theybindandblockvoltage-sensitivecalciumchannels(VSCC). ωconotoxinMVIIA blocks N-typevoltage-gatedcalciumchannels(Cav2.2/CACNA1B). ωconotoxinMVIIA isavailableasanalgesicdrugunderthenamePrialt®.Itblocksacutepaininpatientswhonolongerobtainrelieffromopiatedrugs.Itis100to1.000timesmorepotentthanmorphine.Thistoxinblockscalciumchannelsanddisablesnervesthattransmitpainsignals.Description: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-NH2Disulfidebonds: Cys1-Cys16,Cys8-Cys20 andCys15-Cys25Length(aa): 25Formula: C102H172N36O32S7MolecularWeight: 2639.18DaAppearance:WhitelyophilizedsolidSolubility: waterandsalinebufferCASnumber: [107452-89-1]Source: SyntheticPurityrate: >97%Reference:Ziconotide:neuronalcalciumchannelblockerfortreatingseverechronicpainZiconotide(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:15578997NeuronalcalciumchannelantagoNISTs.Discriminationbetweencalciumchannelsubtypesusingomega-conotoxinfromConusmagusvenomTheomega-conotoxinsfromthevenomoffish-huntingconesnailsareprobablythemostusefulofpresentlyavailableligandsforneuronalCachannelsfromvertebrates.Twoofthesepeptidetoxins,omega-conotoxinsMVIIAandMVIIBfromthevenomofConusmagus,werepurified.Theaminoacidsequencesshowsignificantdifferencesfromomega-conotoxinsfromConusgeographus.Totalsynthesisofomega-conotoxinMVIIAwasachieved,andBIOLOGicallyactiverADIolabeledtoxinwasproducedbyiodination.Althoughomega-conotoxinsfromC.geographus(GVIA)andC.magus(MVIIA)appeartocompeteforthesamesitesinmammalianbrain,inamphibianbrainthehigh-affinitybindingofomegaconotoxinMVIIAhasnarrowerspecificity.Inthissystem,itisdemonstratedthatacombinationoftwoomega-conotoxinscanbeusedforbiochemicallydefiningreceptorsubtypesandsuggestedthatthesecorrespondtosubtypesofneuronalCa2+channels.Olivera,B.M.,etal.(1987)Neuronalcalciumchannelantagonists.Discriminationbetweencalciumchannelsubtypesusingomega-conotoxinfromConusmagusvenom,Biochemistry.PMID:2441741Pharmacotherapeuticpotentialofomega-conotoxinMVIIA(SNX-111),anN-typeneuronalcalciumchannelblockerfoundinthevenomofConusmagusBowersoxSS,LutherR.Pharmacotherapeuticpotentialofomega-conotoxinMVIIA(SNX-111),anN-typeneuronalcalciumchannelblockerfoundinthevenomofConusmagus. Toxicon. PMID: 9792182