| Formulation | Hepesbufferedsaline |
| Storage | -80°C |
| Purity | >95%bySDS-PAGE |
| ActivityDetermination | Clottingassay |
| ShelfLife(properlystored) | 12months |
Thedomainstructureofprothrombinisrepresented,where:GLA=regioncontainingγ-carboxyglutamicacidresidues,KRINGLE=regionsofinternalsequencehomology,CATALYTICDOMAIN=regioncontainingtheserineproteasecatalytictriad.ArrowsindicatethesiteswhichareproteolyticallycleavedbyfactorXaduringactivationofthezymogen.
SampleGelInformation:
| Gel | Novex4-12%Bis-Tris |
|---|---|
| Load | 1µgperlane;purifiedhumanprothrombin |
| Buffer | MOPS |
| Standard | SeeBluePlus2;Myosin(191kDa),PhosphorylaseB(97kDa),BSA(64kDa),GlutamicDehydrogenase(51kDa),AlcoholDehydrogenase(39kDa),CarbonicAnhydrase(28kDa),MyoglobinRed(19kDa),Lysozyme(14kDa) |
Overview:
ProthrombinisavitaminK-dependentplasmaproteinwhichissynthesizedintheliver(1).Priortosecretionintoplasma,prothrombinundergoespost-translationalmodificationbyavitaminK-dependentcarboxylasewhichconvertstenspecificglutamicacidresiduestoγ-carboxyglutamicacid(gla).Thetenglaresiduesarelocatedwithinthefirst40aminoacidsofthematureproteinandcontributetotheABIlityofprothrombintobindtonegativelychargedphospholipidmembranes.Prothrombincontainstworegionsofinternalhomologywhicharereferredtoas"kringle"structures.Theseregionsofconspicuoussecondarystructurearelocatedbetweenresidues40and270ofthematureplasmaproteinandreplacethegrowthfactordomainsfoundinseveralotherplasmaserineproteases.Thusfar,nofunctionhasbeenascribedtotheseregions,butthereissUSPicionthattheymayplayaroleinoneofseveralbinaryproteininteractionsinvolvingprothrombin.Thematuresinglechainproteincirculatesinplasmaasazymogenand,duringcoagulation,isproteolyticallyactivatedtothepotentserineproteaseα-thrombin.Thisproteolysisiscatalyzedbytheprothrombinaseenzymecomplex.Duringactivation,prothrombiniscleavedatArg271-Thr272(human)/Arg273-Thr274(bovine)andatArg320-Ser321(human)/Arg323-Ser324(bovine)toa"pro"fragment(fragment1.2)andthrombin,thelatterofwhichiscomposedoftwochainscovalentlylinkedbyadisulfidebond.Inthecaseofhumanprothrombin/thrombin,thereisanadditionalthrombinfeed-backcleavageatArg284-Thr285resultinginanadditional13aminoacidsbeingremovedfromthematurethrombin“A”chain.
HumanprothrombinispreparedfromfreshfrozenhumanplasmaasdescribedbyBajajandcoworkers(2).BovineprothrombinispreparedfromfreshbovineplasmausingamodificationoftheproceduredescribedbyOwenandcoworkers(3).Purifiedprothrombinissuppliedin50%(vol/vol)glycerol/H2Oandshouldbestoredat-20oC.PurityisdeterminedbySDS-PAGEanalysis,andactivityismeasuredbyclottingand/orchromogenicsubstrateassay,followingconversionofprothrombintothrombin.
Properties:
| Localization | Plasma | |||||||
|---|---|---|---|---|---|---|---|---|
| Plasmaconcentration | 100µg/ml(1) | |||||||
| Molecularweight | 72,000(1,4,5). Fragments: ProthrombinFragment1-21,700 ProthrombinFragment2-12,866 ProthrombinFragment1.2-34,566 PrethrombinFragement1-49,900 PrethrombinFragment2-37,580 | |||||||
| Extinctioncoefficient |
| |||||||
| Isoelectricpoint | 4.7-4.9(human)(6) 4.4-4.9(bovine)(6) | |||||||
| Structure | singlechain,NH2-terminalgladomain,twokringleregions | |||||||
| Percentcarbohydrate | 8.2%(human)(4) 10.0%(bovine)(5) | |||||||
| Post-translationalmodifications | tenglaresidues(4,5) |
