Muscarinictoxin7(MT7–m1-toxin1)hasbeenisolatedfromthevenomofthegreenmamba(DendroaspisAngusticeps).MT7potentlyblocksM1-subtypeofmuscarinicacetylcholinereceptorsatasubnanomolaraffintiy.MuscarinicacetylcholinereceptorsareG-proteincoupledreceptorsthatmediatethemetabotropiceffectsofacetylcholine.M1-typemuscarinicacetylcholinereceptorsarewellknowntherapeutictargetstoimprovecognitivefunctionsinpatientswithAlzheimerdisease.ContrarytomanyligandsthattargetmAChRs(pirenzepine,carbamoylcholinechloride,4-DAMPoratropine),MT7isthemostselectiveM1-subtypeantagoNISTasitisabout10,000timesmoreselectiveforM1-subtypethanothersubtypes.MT7toxinisanidealtooltoidentifythemuscarinicreceptorsubtypeexpressionintissuesforexample.MT7toxinbelongstothethreefingertoxinfamilysuchasrho-Da1a.
Recentlyquoted
Description:
AAsequence:LTC3VKSNSIWFPTSEDC17PDGQNLC24FKRWQYISPRMYDFTRGC42AATC46PKAEYRDVINC57C58GTDKC63NK
Disulfidebonds:Cys3-Cys24,Cys17-Cys42,Cys46-Cys57,Cys58-Cys63
Length(aa):65
Formula:C322H484N90O98S9
MolecularWeight: 7472.53Da
Appearance:Whitelyophilizedsolid
Solubility: waterandsalinebuffer
CASnumber: notavailable
Source:synthetic
Purityrate: >98%
Reference:
Structuraldeterminantsfortheinteractionsbetweenmuscarinictoxin7andmuscarinicacetylcholinereceptors
XuJ.,etal.(2015)Structuraldeterminantsfortheinteractionsbetweenmuscarinictoxin7andmuscarinicacetylcholinereceptors.JMolRecognit.PMID:25683330
Muscarinicacetylcholinereceptors(mAChRs)havefivesubtypesandplaycrucialrolesinvariousphysiologicalfunctionsandpathophysiologicalprocesses.PoorsubtypespecificityofmAChRmodulatorshasbeenanobstacletodiscovernewtherapeuticagents.Muscarinictoxin7(MT7)isanaturalpeptidetoxinwithhighselectivityfortheM1receptor.Withthreetofiveresiduessubstituted,M3,M4,andM5receptormutantscouldbindtoMT7atnanomolarconcentrationastheM1receptor.However,thestructuralmechanismsexplainingMT7-mAChRsbindingarestilllargelyunknown.Inthisstudy,weconstructed10complexmodelsofMT7andeachmAChRsubtypeoritsmutant,performedmoleculardynamicssimulations,andcalculatedthebindingenergiestoinvestigatethemechanisms.OurresultssuggestedthatthestructuraldeterminantsfortheinteractionsonmAChRswerecomposedofsomecriticalresidueslocatedseparatelyintheextracellularloopsofmAChRs,suchasGlu4.56,Leu4.60,Glu/Gln4.63,Tyr4.65,Glu/Asp6.67,andTrp7.35.ThesubtypespecificityofMT7wasattributedtothenon-conservedresiduesatpositions4.56and6.67.ThesestructuralmechanismscouldfacilitatethediscoveryofnovelmAChRmodulatorswithhighsubtypespecificityandenhancetheunderstandingoftheinteractionsbetweenligandsandG-protein-coupledreceptors.
MolecularconversionofmuscarinicAcetylcholineReceptorM5toMuscarinicToxin(MT7)bindingprotein
RondinelliS.,etal.(2011)MolecularconversionofmuscarinicAcetylcholineReceptorM5toMuscarinicToxin(MT7)bindingprotein.Toxins.PMID:22174976
Muscarinictoxin7(MT7)isamambavenompeptidethatbindsselectivelytotheM(1)muscarinicacetylcholinereceptor.Wehavepreviouslyshownthatthesecond(ECL2)andthird(ECL3)extracellularloopsoftheM(1)receptorarecriticallyinvolvedinbindingthepeptide.InthisstudyweusedamutagenesisapproachontheM(5)subtypeofthereceptorfamilytofindoutifthispossessesasimilarstructuralarchitectureintermsoftoxinbindingastheM(1)receptor.AnM(5)receptorconstruct(M(5)-E(175)Y(184)E(474)),mutatedattheformerlydecipheredcriticalresiduesonECL2and3,gainedtheABIlitytobindMT7,butwithratherlowaffinityasdeterminedinafunctionalassay(apparentK(i)=24nM;apparentK(i)forM(1)=0.5nM).Afterscreeningfordifferentdomainsandresidues,wefoundaspecificresidue(P(179)toLinM(5))inthemiddleportionofECL2thatwasnecessaryforhighaffinitybindingofMT7(M(5)-EL(179)YE,apparentK(i)=0.5nM).MutationofP(179)toAconfirmedarolefortheleucinesidechaininthebindingofMT7.TogethertheresultsrevealnewbindinginteractionsbetweenreceptorsandtheMT7peptideandstrengthenthehypothesisthatECL2sequenceisofutmostimportanceforMTbindingtomuscarinicreceptors.
DifferentinteractionbetweenMT7toxinandthehumanmuscarinicM1ReceptorinitsfreesanN-Methylscopolamineoccupiedstates.
Fruchart-GaillardC.,etal.(2008)DifferentinteractionbetweenMT7toxinandthehumanmuscarinicM1ReceptorinitsfreesanN-Methylscopolamineoccupiedstates. MolPharmacol.PMID:18784346
MuscarinicMT7toxinisahighlyselectiveandpotentantagonistoftheM(1)subtypeofmuscarinicreceptorandactsbybindingtoanallostericsite.ToidentifythemoleculardeterminantsbywhichMT7toxininteractswiththisreceptorinitsfreeandNMS-occupiedstates,theeffectontoxinpotencyofalaninesubstitutionwasevaluatedinequilibriumandkineticbindingexperimentsaswellasinfunctionalassays.ThedeterminationofthecrystallographicstructureofanMT7-derivative(MT7-diiodoTyr51)allowedtheselectionofcandidateresiduesthatareaccessIBLeandpresentonbothfacesofthethreetoxinloops.TheequilibriumbindingdataareconsistentwithnegativecooperativitybetweenN-methylscopolamine(NMS)andwild-typeormodifiedMT7andhighlightthecriticalroleofthetipofthecentralloopofthetoxin(Arg34,Met35Tyr36)initsinteractionwiththeunoccupiedreceptor.Examinationofthepotencyofwild-typeandmodifiedtoxinstoallostericallydecreasethedissociationrateof[(3)H]NMSallowedtheidentificationoftheMT7residuesinvolvedinitsinteractionwiththeNMS-occupiedreceptor.Incontrasttotheresultswiththeunoccupiedreceptor,themostimportantresidueforthisinteractionwasTyr36inloopII,assistedbyTrp10inloopIandArg52inloopIII.ThecriticalroleofthetipsoftheMT7loopswasalsoconfirmedinfunctionalexperiments.ThehighspecificityoftheMT7-M(1)receptorinteractionexploitsseveralMT7-specificresiduesandrevealsadifferentmodeofinteractionofthetoxinwiththefreeandNMS-occupiedstatesofthereceptor.
MuscarinicToxin7selectivityisdictatedbyextracellularreceptorloops
KukkonenA.,etal.(2004)MuscarinicToxin7selectivityisdictatedbyextracellularreceptorloops.JBC.PMID: 15452105
Muscarinictoxin7(MT7)isamambavenomproteinantagonistwithextremelyhighselectivityfortheM1muscarinicacetylcholinereceptor.TomapthesitesfortheinteractionofMT7withmuscarinicreceptorswehaveusedchimericM1:M3receptorsandsite-directedmutagenesisoftheM3andM4receptorsubtypes.TwoGluresiduesinM1,oneinextracellularloop2andoneinextracellularloop3,werefoundtobeimportantforthehighaffinitybindingofMT7.SubstitutionofthecorrespondingLysresiduesintheM3receptorwithGluconvertedtheM3mutanttoanMT7bindingreceptor,albeitwithloweraffinitycomparedwithM1.APhe–>Tyrsubstitutioninextracellularloop2ofM3togetherwiththe2GlumutationsgeneratedareceptorwithanincreasedMT7affinity(apparentKi=0.26nMinafunctionalassay)comparedwiththeM1receptor(apparentKi=1.31nM).TheimportanceoftheidentifiedaminoacidresidueswasconfirmedwithamutatedM4receptorconstructs.TheresultsindicatethatthehighselectivityofMT7fortheM1receptordependsonveryfewresidues,thusprovidinggoodProspectsforfuturedesignandsynthesisofmuscarinicreceptor-selectiveligands.
EffectsofmuscarinictoxinsMT2andMT7,fromgreenmambavenom,onm1,m3andm5muscarinicreceptorsexpressedinChineseHamsterOvarycells
BradleyKN.etal.(2003)EffectsofmuscarinictoxinsMT2andMT7,fromgreenmambavenom,onm1,m3andm5muscarinicreceptorsexpressedinChineseHamsterOvarycells.Toxicon.PMID:12565740
Severalsmallproteinscalledmuscarinictoxins(MTs)havebeenisolatedfromvenomofgreenmamba(Dendroaspisangusticeps).TheyhavepreviouslybeenshowninrADIoligandbindingstudiestohavehighselectivityandaffinityforindividualmuscarinicreceptorsubtypes,butlessisknownoftheirfunctionaleffects.ThisstudyhasexaminedtheactionsoftwooftheseMTs,MT2andMT7,usingchangesincytosolicCa(2+)([Ca(2+)](i))measuredusingthefluorescentindicatorfura-2inChineseHamsterOvary(CHO)cellsstablytransfectedwithindividualmuscarinicreceptorsubtypes,m1,m3andm5.MT2activatedthem1receptor:atconcentrationsabove100nMitcausedsignificantandconcentration-dependentincreasesin[Ca(2+)](i).From25to800nMMT2alsoproducedincreasesin[Ca(2+)](i)byactivatingm3receptors,althoughtheseincreasesin[Ca(2+)](i)werenotstrictlyconcentration-dependentwithonlyintermittentresponsesbeingrecorded(i.e.itwasnotalwayspossibletoobtainaresponsetotheagonistwitheachapplicationofthecompound).MT2(800-1600nM)alsocausedsignificantincreasesin[Ca(2+)](i)inCHOcellsexpressingthem5muscarinicreceptorsubtype.MT7(1microM)displayednoagonistactivityatanyofthemuscarinicreceptorsbutwasapotentnon-competitiveantagonist(at20nM)atthem1muscarinicreceptorsubtype.Ithadnoantagonistactivityatthem3orm5subtypes.TheseresultsindicatethatMT7isahighlyspecificantagonistatthem1muscarinicreceptorsubtypeassuggestedbyresultsfromradioligandbindingstudies.However,MT2islessselectiveforthem1muscarinicreceptorthanpreviouslydescribedasitalsoexhibitsagonistactivityatthem3andm5muscarinicreceptors,whichwasnotdetectedinradioligandbindingstudies.
InhibitionofacetylcholinemuscarinicM1receptorfunctionbytheM1-selectiveligandmuscarinictoxin7(MT-7)
OlianasMC.,etal.(2000)InhibitionofacetylcholinemuscarinicM1receptorfunctionbytheM1-selectiveligandmuscarinictoxin7(MT-7).BrJPharmacol.PMID:11015294
MT-7(1–30nM),apeptidetoxinisolatedfromthevenomofthegreenmambaDendroaspisangusticepsandpreviouslyfoundtobindselectivelytothemuscarinicM(1)receptor,inhibitedtheacetylcholine(ACh)-stimulated[(35)S]-guanosine-5′-O-(3-thio)triphosphate([(35)S]-GTPgammaS)bindingtomembranesofChinesehamsterovary(CHO)cellsstablyexpressingtheclonedhumanmuscarinicM(1)receptorsubtype.MT-7failedtoaffecttheACh-stimulated[(35)S]-GTPgammaSbindinginmembranesofCHOcellsexpressingeithertheM(2),M(3)orM(4)receptorsubtype.InN1E-115neuroblastomacellsendogenouslyexpressingtheM(1)andM(4)receptorsubtypes,MT-7(0.3–3.0nM)inhibitedthecarbachol(CCh)-stimulatedinositolphosphatesaccumulation,butfailedtoaffecttheCCh-inducedinhibitionofpituitaryadenylatecyclaseactivatingpolypeptide(PACAP)38-stimulatedcyclicAMPaccumulation.InbothCHO/M(1)andN1E-115cellstheMT-7inhibitionconsistedinadecreaseofthemaximalagonisteffectwithminimalchangesintheagonistEC(50)value.InCHO/M(1)cellmembranes,MT-7(0.05–25nM)reducedthespecificbindingof0.05,1.0and15nM[(3)H]-N-methylscopolamine([(3)H]-NMS)inaconcentration-dependentmanner,butfailedtocauseacompletedisplacementoftheradioligand.Moreover,MT-7(3nM)decreasedthedissociationrateof[(3)H]-NMSbyabout5fold.CHO/M(1)cellmembranespreincubatedwithMT-7(10nM)andwashedbycentrifugationandresUSPensiondidnotrecovercontrol[(3)H]-NMSbindingforatleast8hat30degreesC.ItisconcludedthatMT-7actsasaselectivenoncompetitiveantagonistofthemuscarinicM(1)receptorsbybindingstablytoanallostericsite.
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。
本网站将在规定时间内给予删除等相关处理。
