ω-agatoxin-IVA (ω-AGAIVA) isapeptideoriginallyisolatedfromfunnelweb-spidervenomAgelenopsisaperta.Thispeptideisaspecificblockerof P/Q-typecalciumchannel(Cav2.1). Ithasbeenreportedthat ω-agatoxinIVA isapotentblockerofvoltage-gatedcalciumchannelsininsectandvertebratecentralneurons.Thebindingsitefor ω-agatoxinIVA hasbeenlocalizedinparttotheextracellularS3–S4loopinrepeatIVoftheα-1A Ca2+ channels,whichisproximaltotheS4sensordomain.Thisiscoherentwithitsfunctionaleffect(nopore-blockingactivity,butgatingmodifierbyashiftofchannelactivationtowardsmoredepolarizedpotentials).Thismakesthistoxinavoltage-dependentblockerofP/Qcalciumchannels.
Newproductcitation
AAsequence:Lys-Lys-Lys-Cys4-Ile-Ala-Lys-Asp-Tyr-Gly-Arg-Cys12-Lys-Trp-Gly-Gly-Thr-Pro-Cys19-Cys20-Arg-Gly-Arg-Gly-Cys25-Ile-Cys27-Ser-Ile-Met-Gly-Thr-Asn-Cys34-Glu-Cys36-Lys-Pro-Arg-Leu-Ile-Met-Glu-Gly-Leu-Gly-Leu-Ala-OH
Disulfidebonds:Cys4-Cys20,Cys12-Cys25,Cys19-Cys36andCys27-Cys34
Length(aa):48
Formula:C217H360N68O60S10
MolecularWeight:5202.48Da
Appearance:Whitelyophilizedsolid
Solubility:waterandsalinebuffer
CASnumber:145017-83-0
Source:Synthetic
Purityrate:>97%
Voltage-dependentcalciumchannelsmediatecalciumentryintoneurons,whichiscrucialformanyprocessesinthebrainincludingsynaptictransmission,dendriticspiking,geneexpressionandcelldeath.Manytypesofcalciumchannelsexistinmammalianbrains,buthigh-affinityblockersareavailableforonlytwotypes,L-typechannels(targetedbynimodipineandotherdihydropyridinechannelblockers)andN-typechannels(targetedbyomega-conotoxin).Inasearchfornewchannelblockers,wehaveidentifiedapeptidetoxinfromfunnelwebspidervenom,omega-Aga-IVA,whichisapotentinhibitorofbothcalciumentryintoratbrainsynaptosomesandof‘P-type’calciumchannelsinratPurkinjeneurons.omega-Aga-IVAwillfacilitatecharacterizationofbraincalciumchannelsresistanttoexistingchannelblockersandmayassistinthedesignofneuroprotectivedrugs.
MintzI.M., etal. (1992)P-typecalciumchannelsblockedbythespidertoxinomega-Aga-IVA. Nature . PMID:1311418
P-typeandQ-typecalciumchannelsmediateneurotransmitterreleaseatmanysynapsesinthemammaliannervoussystem.Thealpha1Acalciumchannelhasbeenimplicatedintheetiologiesofconditionssuchasepisodicataxia,epilepsyandfamilialmigraine,andsharesseveralpropertieswithnativeP-andQ-typechannels.However,theexactrelationshipbetweenalpha1AandP-andQ-typechannelsisunknown.Herewereportthatalternativesplicingofthealpha1Asubunitgeneresultsinchannelswithdistinctkinetic,pharmacologicalandmodulatoryproperties.Overall,theresultsindicatethatalternativesplicingofthealpha1AgenegeneratesP-typeandQ-typechannelsaswellasmultiplephenotypicvariants.
BourinetE,etal.(1999)Splicingofalpha1AsubunitgenegeneratesphenotypicvariantsofP-andQ-typecalciumchannels. NatNeurosci. PMID:10321243
AgatoxinsfromAgelenopsisapertavenomtargetthreeclassesofionchannels,includingtransmitter-activatedcationchannels,voltage-activatedsodiumchannels,andvoltage-activatedcalciumchannels.Thealpha-agatoxinsarenon-competitive,use-dependentantagoNISTsofglutamatereceptorchannels,andproducerapidbutreversIBLeparalysisininsectprey.Theiractionsarefacilitatedbythemicro-agatoxins,whichshiftvoltage-dependentactivationofneuronalsodiumchannelstomorenegativepotentials,causingspontaneoustransmitterreleaseandrepetitiveactionpotentials.Theomega-agatoxinstargetneuronalcalciumchannels,modifyingtheirpropertiesindistinctways,eitherthroughgatingmodification(omega-Aga-IVA)orbyreductionofunitarycurrent(omega-Aga-IIIA).Thealpha-agatoxinsandomega-agatoxinsmodifybothinsectandvertebrateionchannels,whilethemicro-agatoxinsareselectiveforinsectchannels.Agatoxinshavebeenusedasselectivepharmacologicalprobesforcharacterizationofionchannelsinthebrainandheart,andhavebeenevaluatedascandidatebiopesticides.
AdamsME.(2004)Agatoxins:ionchannelspecifictoxinsfromtheAmericanfunnelwebspider,Agelenopsisaperta.Toxicon. PMID:15066410
Voltage-gatedcalciumchannelsarekeysourcesofcalciumentryintothecytosolofmanyexcitabletissues.Anumberofdifferenttypesofcalciumchannelshavebeenidentifiedandshowntomediatespecializedcellularfunctions.Becauseoftheirfundamentalnature,theyareimportanttargetsfortherapeuticinterventionindisorderssuchashypertension,pain,stroke,andepilepsy.Calciumchannelantagonistsfallintooneofthefollowingthreegroups:smallinorganicions,largepeptideblockers,andsmallorganicmolecules.Inorganicionsnonselectivelyinhibitcalciumentrybyphysicalporeocclusionandareoflittletherapeuticvalue.Calcium-channel-blockingpeptidesisolatedfromvariouspredatoryanimalssuchasspidersandconesnailsareoftenhighlyselectiveblockersofindividualtypesofcalciumchannels,eitherbypreventingcalciumfluxthroughtheporeorbyantagonizingchannelactivation.Therearemanystructure-activity-relationclassesofsmallorganicmoleculesthatinteractwithvarioussitesonthecalciumchannelprotein,withactionsrangingfromselectivehighaffinityblocktorelativelynondiscriminatoryactiononmultiplecalciumchannelisoforms.Detailedinteractionswiththecalciumchannelproteinarewellunderstoodforthedihydropyridineandphenylalkylaminedrugclasses,whereasweareonlybeginningtounderstandthemolecularactionsofsomeofthemorerecentlydiscoveredcalciumchannelblockers.Here,weprovideacomprehensivereviewofpharmacologyofhighvoltage-activatedcalciumchannels.
DoeringCJ,ZamponiGW.(2003)Molecularpharmacologyofhighvoltage-activatedcalciumchannels. JBioenergBiomembr. PMID:15000518
Thegatingmodifiertoxinsarealargefamilyofproteintoxinsthatmodifyeitheractivationorinactivationofvoltage-gatedionchannels.omega-Aga-IVAisagatingmodifiertoxinfromspidervenomthatinhibitsvoltage-gatedCa(2+)channelsbyshiftingactivationtomoredepolarizedvoltages.WeidentifiedtwoGluresiduesneartheCOOH-terminaledgeofS3inthealpha(1A)Ca(2+)channel(oneinrepeatIandtheotherinrepeatIV)thatalignwithGluresiduespreviouslyimplicatedinformingthebindingsitesforgatingmodifiertoxinsonK(+)andNa(+)channels.WefoundthatmutationoftheGluresidueinrepeatIoftheCa(2+)channelhadnosignificanteffectoninhibitionbyomega-Aga-IVA,whereastheequivalentmutationoftheGluinrepeatIVdisruptedinhibitionbythetoxin.TheseresultssuggestthattheCOOH-terminalendofS3withinrepeatIVcontributestoformingareceptorforomega-Aga-IVA.ThestrongpredictivevalueofpreviousmappingstudiesforK(+)andNa(+)channeltoxinsarguesforaconservedbindingmotifforgatingmodifiertoxinswithinthevoltage-sensingdomainsofvoltage-gatedionchannels.
WinterfieldJR,SwartzKJ.(2000)Ahotspotfortheinteractionofgatingmodifiertoxinswithvoltage-dependentionchannels. JGenPhysiol. PMID:11055992
Insectshaveamuchsmallerrepertoireofvoltage-gatedcalcium(Ca(V))channelsthanvertebrates.DrosophilamelanogasterharborsonlyasingleorthologofeachofthevertebrateCa(V)1,Ca(V)2,andCa(V)3subtypes,althoughitsbasalinventoryisexpandedbyalternativesplicingandeditingofCa(V)channeltranscripts.Nevertheless,thereappearstobelittlefunctionalplasticitywithinthislimitedpanelofinsectCa(V)channels,sincesevereloss-of-functionmutationsingenesencodingthepore-formingalpha1subunitsinDrosophilaareembryoniclethal.Sincetheprimaryroleofspidervenomistoparalyzeorkillinsectprey,itisnotsurprisingthatmost,ifnotall,spidervenomscontainpeptidesthatpotentlymodifytheactivityofthesefunctionallycriticalinsectCa(V)channels.Unfortunately,ithasprovendifficulttodeterminethepreciseionchannelsubtypesrecognizedbythesepeptidetoxinssinceinsectCa(V)channelshavesignificantlydifferentpharmacologytotheirvertebratecounterparts,andclonedinsectCa(V)channelsarenotavailableforelectrophysiologicalstudies.However,biochemicalandgeneticstudiesindicatethatsomeofthesespidertoxinsmightultimatelybecomethedefiningpharmacologyforcertainsubtypesofinsectCa(V)channels.ThisreviewfocusesonpeptidicspidertoxinsthatspecificallytargetinsectCa(V)channels.Inadditiontoprovidingnovelmoleculartoolsforionchannelcharacterization,someofthesetoxinsarebeingusedasleadstodevelopnewmethodsforcontrollinginsectpests.
KingGF.(2007)ModulationofinsectCa(v)channelsbypeptidicspidertoxins. Toxicon. PMID:17197008
omega-toxinsspecificallyblockcertainCa2+channelsinmammalianneuronsaswellasindorsalunpairedmedianneuronsisolatedfromthecockroachPeriplanetaamericana.InthesecockroachneuronsboththeP/Q-typeblockersomega-agatoxinIVAandomega-conotoxinMVIICbutnottheN-typeCa2+channelblockeromega-conotoxinGVIAaffectedfastNa+currentssensitivetotetrodotoxinandveratridine.Bothomega-toxinsenhancedNa+currentdecayandthusdecreasedtheamplitudesofthepeakcurrents.Theyalsoledtoaslowerrecoveryfrominactivation.Toxineffectsdevelopingwithinafewminwereotremoveduponwashing.Theywerenotuse-dependent.Thedescriptionoftheeffectofomega-conotoxinMVIIConcurrentkineticsintermsoftheHodgkin-Huxleymodelrevealedthatsteady-stateparameterswerenotaffectedwhereasthetimeconstantofinactivationwasconsiderablyreduced.Undercontrolconditions,theinactivationtimeconstantissimilartothetimeconstantofrecoveryfrominactivation.Thetoxin-inducedincreaseofthelattertimeconstantandthedecreaseoftheinactivationtimeconstantindicatethatinactivationcannolongerbedescribedbyfirst-orderkinetics.
WicherD,PenzlinH.(1998)omega-ToxinsaffectNa+currentsinneurosecretoryinsectneurons. ReceptorsChannels. PMID:9826912
Ca2+currentsindorsalunpairedmedian(DUM)neuronsisolatedfromthefifthaBDominalganglionofthecockroachPeriplanetaamericanawereinvestigatedwiththewholecellpatch-clamptechnique.Onthebasisofkineticandpharmacologicalproperties,twodifferentCa2+currentswereseparatedinthesecells:mid/low-voltage-activated(M-LVA)currentsandhigh-voltage-activated(HVA)currents.M-LVAcurrentshadanactivationthresholdof-50mVandreachedmaximalpeakvaluesat-10mV.Theyweresensitivetodepolarizedholdingpotentialsanddecayedveryrapidly.ThedecaywaslargelyCa2+dependent.M-LVAcurrentswereeffectivelyblockedbyCd2+medianinhibitingconcentration(IC50=9microM),buttheyalsohadaremarkablesensitivitytoNi2+(IC50=19microM).M-LVAcurrentswereinsensitivetovertebrateLVAchannelblockerslikeflunarizineandamiloride.Thecurrentswere,however,potentlyblockedbyomega-conotoxinMVIIC(1microM)andomega-agatoxinIVA(50nM).Theblockingeffectsofomega-toxinsdevelopedfast(timeconstanttau=15s)andwerefullyreversibleafterwash.HVAcurrentsactivatedpositiveto-30mVandshowedmaximalpeakcurrentsat+10mV.Theywereresistanttodepolarizedholdingpotentialsupto-50mVanddecayedinalesspronouncedmannerthanM-LVAcurrents.HVAcurrentswerepotentlyblockedbyCd2+(IC50=5microM)butlessaffectedbyNi2+(IC50=40microM).Thesecurrentswerereducedbyphenylalkylamineslikeverapamil(10microM)andbenzothiazepineslikediltiazem(10microM),buttheywereinsensitivetodihydropyridineslikenifedipine(10microM)andBAYK8644(10microM).FurThermore,HVAcurrentsweresensitivetoomega-conotoxinGVIA(1microM).Thetoxin-inducedreductionofcurrentsappearedslowly(tauapproximately120s)andtherecoveryafterwashwasincompleteinmostcases.Thedihydropyridineinsensitivityofthephenylalkylamine-sensitiveHVAcurrentsisapropertythecockroachDUMcellssharewithotherinvertebrateneurons.ComparedwithCa2+currentsinvertebrates,theDUMneuroncurrentdifferconsiderablyfromthepresentlyknowntypes.Althoughtherearesomesimilaritiesconcerningkinetics,thepharmacologicalprofileofthecockroachCa2+currentsespeciallyisverydifferentfromprofilesalreadydescribedforvertebratecurrents.
WicherD,PenzlinH.(1997)Ca2+currentsincentralinsectneurons:electrophysiologicalandpharmacologicalproperties. JNeurophysiol. PMID:9120560
Smartox Biotechnolgy的多肽毒素产品如下:
1. 作用于钠离子通道(Sodium channel)的毒素
Toxin name | Catalog # | Target |
Phrixotoxin-3 | 13PHX003 | Selective blocker of Nav1.2 |
µ-conotoxin GIIIB | CON020 | Selective blocker of Nav1.4 |
µ-conotoxin CnIIIC | CON021 | Selective blocker of Nav1.4 |
μ-conotoxin PIIIA | 08CON006 | Selective blocker of Nav1.4 |
Jingzhaotoxin-III | 12JZH003 | Selective blocker of Nav1.5 |
ProTx-II | 07PTX002 | Selective blocker of Nav1.7 |
ProTx-II Biotin | 12PTB002 | Selective blocker of Nav1.7 |
ProTx-I | 12PTX001 | Blocker of Nav1.8, Nav1.2, Nav1.5, Nav1.7 |
Huwentoxin-I | 07HWT001 | Blocker of TTX-S |
Huwentoxin-IV | 08HWT002 | Blocker of TTX-S |
Hainantoxin-III | 13HTX003 | Blocker of TTX-S |
Hainantoxin-IV | 12HTX001 | Blocker of TTX-S |
GsAF-I | 12GSF001 | Blocker of TTX-S |
GsAF-II | 12GSF002 | Blocker of TTX-S |
2. 作用于钾离子通道(Potassium channel)的毒素
Toxin name | Catalog # | Target |
KCa channels | ||
Apamin 蜜蜂神经毒素 | 08APA001 | SK1, SK2, SK3 |
Charybdotoxin 蝎毒素 | 11CHA001 | KCa1.1, KCa3.1 - Kv1.2, Kv1.3, Kv1.6 |
Iberiotoxin | 12IBX001 | KCa1.1 |
Leiurotoxin 1 (Scyllatoxin) | 10LEI001 | SK1, SK2, SK3 |
Tamapin | 10TAM001 | SK1, SK2, SK3 |
Kaliotoxin-1 | 08KTX002 | BK, Kv1.1, Kv1.2, Kv1.3 |
Kv channels | ||
ShK | 08SHK001 | Kv1.3, Kv1.1, Kv1.4, Kv1.6 |
TMR-ShK | SAT001 | Kv1.3, Kv1.1 |
Margatoxin | 08MAG001 | Kv1.3 |
(Dap22)-ShK | 13SHD001 | Kv1.3 |
ADWX-1 | 13ADW001 | Kv1.3 |
HsTx1 | 08NEU001 | Kv1.3, Kv1.2 |
Agitoxin-2 | 13AGI002 | Kv1.3, Kv1.1 |
Maurotoxin | 08MAR001 | Kv1.2, KCa3.1 |
Guangxitoxin 1E | 11GUA002 | Kv2.1, Kv2.2 |
Stromatoxin 1 NEW | SCT01 | Kv2.1, Kv2.2 |
Kaliotoxin-1 | 08KTX002 | BK, Kv1.1, Kv1.2, Kv1.3 |
Charybdotoxin | 11CHA001 | KCa1.1, KCa3.1 - Kv1.2, Kv1.3, Kv1.6 |
Phrixotoxin-2 | PHX002 | Kv4.2, Kv4.3 |
AmmTx3 NEW | AMX001 | A-type potassium channels |
Inwardly rectifying potassium channels | ||
TertiapinQ | 08TER001 | Kir1.1, Kir3.1/3.4, Kir3.1/3.2-KCa1.1 |
hERG/Kv11.1 | ||
BeKm-1 | 13BEK001 | ERG1 |
3. 作用于钙离子通道(Calcium channel)的毒素
Toxin name | Catalog # | Target |
High voltage-gated Ca2+ channels | ||
ω-agatoxin IVA | 11AGA001 | P/Qtype |
ω-Conotoxin MVIIC | 08CON002 | P/Qtype, N-type |
ω-Conotoxin MVIIA | 08CON001 | N-type |
ω-Conotoxin GVIA | 08CON003 | N-type |
ω-Conotoxin SO3 | 08CON013 | N-type |
Huwentoxin I | 07HWT001 | N-type |
ProTx-II | 07PTX002 | T-type, L-type |
Intermediate voltage-gated Ca2+ channels | ||
SNX482 | 08SNX002 | R-type |
Low voltage-gated Ca2+ channels | ||
ProTx-I | 12PTX001 | T-type |
ProTx-II | 07PTX002 | T-type, L-type |
Ryanodine receptors | ||
Maurocalcine | 07PAU001 | Ryr1 |
4. 作用于氯离子通道(Chloride channel)的毒素
Toxin name | Catalog # | Target |
Chlorotoxin | 08CHL001 | Blocker of small conductance Cl- channels |
GaTx1 | 13GTX001 | Selective blocker of CFTR channel |
GaTx2 | 10GTX002 | Selective blocker of ClC-2 channel |
5. 作用于乙酰胆碱受体(Acetylcholine receptor)的毒素
Toxin name | Catalog # | Target |
α-conotoxin PeIA | 13CON017 | α9α10, α3β2 subunits |
α-Conotoxin PrXA | 13CON016 | α1/β1/ε/δ, α1/β1/γ/δ subunits |
Waglerin-1 | 12WAG001 | MusclenAChR |
α-conotoxin MI | 08CON012 | α1/δsubunits |
α-conotoxin GI | 08CON005 | α/δsite |
α-conotoxin IMI | 08CON011 | α7 homomeric nAChR |
α-conotoxin GID | CON019 | Blocker of α3β2, α7 and α4β2 nAChRs |
6. 含N-甲基-D-天冬氨酸NR2B
(NMDA, NR2B containing N-methyl-D-aspartate)
Conantokin-G
选择性、特异性抑制含NR2B的NMDAR。Conantokin-G能剂量依赖性抑制Ca2+内流,抑制NMDA诱导的兴奋性中毒效应。研究表明,在小鼠皮层神经元,Conantokin-G阻滞NMDA引发的电流信号的IC50值为480 nM。
7. 作用于酸敏感离子通道(ASIC channel, Acid-Sensing Ion Channel)的毒素
Toxin name | Catalog # | Target |
APETx2 | 07APE002 | Selective blocker of ASIC3 |
Psalmotoxin1/PcTx1 | 13PCT001 | Selective blocker of ASIC1a |
Ugr9-1 | 13UGR001 | Blocker of ASIC3 |
8. 作用于瞬时受体电位(TRP channel, transient receptor potential)的毒素
Toxin name | Catalog # | Target |
GsMTx4 | 08GSM001 | TRPC, TRPA |
Vanillotoxin3 | 10VAN003 | Activator of TRPV1 |
ProTx-I | 12PTX001 | Antagonist of TRPA1 |
9. 作用于嘌呤能通道(Purinergic channel)的毒素
Purotoxin-1
选择性抑制P2X3受体。100 nM Purotoxin-1 (PT-1)选择性抑制P2X3受体通道,在大鼠DRG神经元上,使用膜片钳实验表明:PT-1对电压门控通道和TRPV1均无抑制效应。10 µM ATP和100 µM α,β Methylene-ATP浓度下Purotoxin-1对P2X3受体有选择性作用,在该ATP浓度下Purotoxin-1对P2X2和杂化二聚体P2X2/3并无激动作用。Purotoxin-1对疼痛的潜在治疗作用。
10. 作用于其它膜受体通道(Others)的毒素
Smartox Biotechnology还提供其他类型的膜受体抑制剂:
Toxin name | Catalog # | Target |
Morphiceptin | 011CAS001 | Agonist of µ-opoid receptors |
Lys-conopressin G | 11CON14 | Vasopressin-like peptide |
GsMTx4 | 08GSM001 | Mechano sensitive ion channels |
Obtustatin | 10OBT001 | Blocks the binding of α1β1 integrin to collagen IV |
Rho-Conotoxin TIA | CON022 | Blocks α1-adrenergic receptor |
公司简介
Smartox Biotechnology是全球唯一一家专门生产动物毒液多肽毒素,用于细胞离子通道功能研究的生物医药公司。多肽毒素在生物制药领域具有重要的使用价值。
Smartox Biotechnology于2009年由来自Grenoble神经科学研究所(Grenoble Institute of Neuroscience)的Michel De Waard博士创立。Smartox Biotechnology专门研究动物毒液,制作合成多种毒液中的多肽成分(常称为毒素)。De Waard博士研究离子通道与毒素多肽的关系,尤其是鉴定、开发毒素多肽作为治疗性分子或细胞穿透肽(cell penetrating peptides, CPP)。其研究团队在毒液分离,药理性活性肽鉴定、富半胱氨酸肽定性、制作和优化等方面具有独特、丰富的经验。2010年,Smartox Biotechnolgy被法国研究部(Ministry of Research)授予“新兴企业OSEO奖(OSEO prize for emerging businesses)”。
总之,Smartox Biotechnolgy提供一系列高质量、具开创价值的多肽毒素。这些化合物在离子通道 研究中具有高的亲和性和选择性,是相应领域科学研究理想的生物毒素提供商和贴心的合作伙伴。