| Formulation | 50%glycerol/water(v/v) |
| Storage | -20°C |
| Purity | >95%bySDS-PAGE |
| ActivityDetermination | Fibrinogenclottingorchromogenicassay |
| ShelfLife(properlystored) | 12months |
Theserineproteaseα-thrombinisproducedbyproteolyticactivationofthezymogen,prothrombin.Theenzymecomplex,prothrombinase,catalyzestheproteolysisoftwopeptidebondsinprothrombin,whichgivesrisetoanNH2-terminalderivedF1.2regionandtheheterodimer,α-thrombin.Alpha-thrombiniscomposedofan"A"chain(Mr=6000)whichiscovalentlylinkedtoa"B"chain(Mr=31,000)throughasingledisulfidebond.
SampleGelInformation:
| Gel | Novex4-12%Bis-Tris |
|---|---|
| Load | HumanBeta&GammaThrombin,1µgperlane |
| Buffer | MES |
| Standard | SeeBluePlus2;Myosin(188kDa),PhosphorylaseB(98kDa),BSA(62kDa),GlutamicDehydrogenase(49kDa),AlcoholDehydrogenase(38kDa),CarbonicAnhydrase(28kDa),MyoglobinRed(17kDa),Lysozyme(14kDa),Aprotinin(6kDa),Insulin,Bchain(3kDa). |
Overview:
Alpha-thrombinisahighlyspecificserineproteasegeneratedbyproteolyticactivationofthezymogenprothrombin(1).Duringcoagulation,thrombincleavesfibrinogentoformfibrin,leADIngtotheultimatestepincoagulation,theformationofafibrinclot.ThrombinisalsoresponsIBLeforfeedbackactivationoftheprocofactorsfactorVandfactorVIII.ThrombinhasalsobeenreportedtoactivatefactorXIIIandplatelets,andalsofunctionsasavasoconstrictorprotein.Theprocoagulantactivityofthrombinisarrestedintwoways:1)inhibitionbyeitherheparincofactorIIortheantithrombinIII/heparincomplex;or2)complexformationwiththrombomodulin.Formationofthethrombin/thrombomodulincomplexresultsintheinABIlityofthrombintocleavefibrinogenandactivatefactorsVandVIII,butincreasestheefficiencyofthrombinforactivationoftheanticoagulant,proteinC.
ThrombinisatwochainenzymecomposedofanNH2-terminal"A"chain(Mr=6,000)andaCOOH-terminal"B"chain(Mr=31,000)whichremaincovalentlyassociatedthroughasingledisulfidebond.Humanthrombinis13aminoacidsshorterthanthebovinethrombinduetoathrombincleavagesiteonthehumanproteinthatisnotpresentinthebovineprotein.
Thrombinisalsoutilizedforsitespecificcleavageoffusionproteinsexpressedinbacteria(9-11).Athrombinsensitivesiteisincorporatedbetweentherecombinantproteinofinterestandpeptidesorproteinswhichfacilitatepurificationand/orexpression.Thetargetproteinisreleasedfromtheexpressedhybridbycleavagewiththrombin.Thrombincanthenbeeasilyremovedbyaffinitychromatography.
Human,bovineandmousethrombinarepreparedfrompurifiedprothrombinusingamodificationoftheLundbladprocedure(1)asdescribedbyNesheimetal.(2).Thrombinissuppliedin50%(vol/vol)glycerol/H2Oandshouldbestoredat-20oC.PurityisdeterminedbySDS-PAGEanalysisandactivityismeasuredinathrombinspecificclottingassay,andcomparedtostandardizedNIHthrombin.ThrombinisalsoavailablewiththeactivesiteblockedwitheitherDFP,FPRck,orbiotinlyatedFPRck.
CleavageofFusionProteins
Inadditiontoitsbroadapplicationincoagulationresearchthrombincanbeusedforsitespecificcleavageoffusionproteins.Athrombinsensitivesiteisincorporatedbetweentherecombinantproteinofinterestandpeptidesorproteinswhichfacilitatepurificationand/orexpression.Thetargetproteinisreleasedfromtheexpressedhybridbycleavagewiththrombin.Thrombincanthenbeeasilyremovedbyaffinitychromatography.Lottolotconsistencyensuresreproducibleresultseverytime.Forexperimentsinvolvingcellcultures,pleasecontactustodiscusscustom,lowendotoxinlotsdesignatedforcellcultureuse.
Properties:
| Localization | Plasma | |||||||
|---|---|---|---|---|---|---|---|---|
| Modeofaction | Serineproteasewhichcleavesfibrinogentoformfibrin;alsoresponsibleforactivationofproteinC,plateletactivationandfeedbackactivationoftheprocofactors,factorVandfactorVIII | |||||||
| Molecularweigh | 36,700(3-6) | |||||||
| Extinctioncoefficient |
| |||||||
| SpecificActivity | approximately3800NIHunits/mg | |||||||
| Isoelectricpoint | 7.0-7.6(human)(3) | |||||||
| Structure | twosubunits,approximatelyMr=6,000and31,000 | |||||||
| Percentcarbohydrate | approximately5% |
