| Formulation | 50%(vol/vol)Glycerol/H2O |
| MolecularWeight | |
| Storage | -20°C |
| Purity | >95%bySDS-PAGE |
| Compound | |
| Assay | Thrombininhibition |
| ShelfLife(properlystored) | 12months |
| ChemicalFormula |
AntithrombinIIIcontainsthreeintra-chaindisulfidebonds(-S-S-),acarbohydraterichdomain(CHO),anNH2-terminalheparinbindingdomain,andaCOOH-terminalserineproteasebindingdomain.
SampleGelInformation:
| Gel | Novex4-12%Bis-Tris |
|---|---|
| Load | HumanATIII,1µgperlane |
| Buffer | MOPS |
| Standard | SeeBluePlus2;Myosin(191kDa),PhosphorylaseB(97kDa),BSA(64kDa),GlutamicDehydrogenase(51kDa),AlcoholDehydrogenase(39kDa),CarbonicAnhydrase(28kDa),MyoglobinRed(19kDa),Lysozyme(14kDa) |
Overview:
AntithrombinIII(ATIII)isasinglechainglycoproteinwithamolecularweightof58,000.Itisamemberoftheserpin(serineproteaseinhibitor)superfamilyandisconsideredtobethemostimportantinhibitorinthecoagulationcascade(1,2).ATIIIinhibitsawidespectrumofserineproteasesincludingthrombin,factorsIXa,XaandXIa,kallikrein,plasmin,urokinase,C1-esterase,andtrypsin.Themechanismofinhibitioninvolvestheformationofastable1:1complexbetweentheactivesiteoftheproteaseandthescissilebond(Arg385-Ser386)ofATIII.TheactivesiteserineofthrombinhasbeenshowntoformacovalentintermediatewiththeP1aminoacid(Arg385)ofATIII.TherateofinhibitionofserineproteasesbyATIIIisincreasedtovaryingdegreesbyheparin.InthecaseofbeingathrombininhibitororfactorXainhibitor,theinteractionwithATIIIisenhanced3ordersofmagnitudeinthepresenceofheparin.TheinteractionbetweenATIIIandheparininvolvesauniquesequenceofsulfatedandnon-sulfatedmonosaccharideunitsonheparin,andcriticallysineresiduesonATIII.ThebindingofATIIItoheparinoidstructuresonvascularendotheliumhasbeendemonstratedandshowntoenhancetheinhibitionoffactorsIXa,Xa,andthrombin.
ATIIImayalsofunctioninthecomplementcascade.ThebindingofATIIItofluidphasecomplementattack-complexesinserahasbeendemonstrated.Inaddition,theSproteinofcomplement(aninhibitorofthemembraneattack-complex)interfereswiththeATIII/thrombininteraction.
ATIIIispreparedfromfreshfrozenplasmabyheparin-agaroseaffinitychromatography(3).Thepurifiedproteinissuppliedin50%(vol/vol)glycerol/H2Oandshouldbestoredat-20°C.PurityisdeterminedbySDS-PAGEanalysis.
Properties:
| Localization | Plasma | |||||
|---|---|---|---|---|---|---|
| PlasmaConcentration | 150µg/ml | |||||
| Modeofaction | Serineproteaseinhibitor | |||||
| Molecularweight | 58,000(3) | |||||
| Extinctioncoefficient |
| |||||
| IsoelectricPoint | 4.9-5.3(5) | |||||
| Structure | Singlechain,threeintrachaindisulfidebonds(Cys8-Cys128,Cys21-Cys95,Cys239-Cys422)(4),10%a-helix,30-40%b-structure,50%randomcoil(5),scissilebond(Arg385-Ser386) | |||||
| Percentcarbohydrate | 9%(5,7) |
