| Formulation | 50%glycerol/water(v/v) |
| Storage | -20°C |
| Purity | >95%bySDS-PAGE |
| ActivityDetermination | N/A |
| ShelfLife(properlystored) | 12months |
ThedomainstructureofproteinZisrepresented,whereGLA=theregioncontainingγ-carboxyglutamicacidresidues;EGF=theregioncontainingsequenceshomologoustohumanepidermalgrowthfactor;pseudocatalyticdomain=regionhomologoustothecatalyticchainofserineproteaseswhichlackstheactivesiteHisandSerresiduesnormallyconservedinthecatalytictriad.
SampleGelInformation:
| Load | HumanProteinZ,1µgperlane |
|---|---|
| Buffer | MOPS |
| Standard | SeeBluePlus2;Myosin(191kDa),PhosphorylaseB(97kDa),BSA(64kDa),GlutamicDehydrogenase(51kDa),AlcoholDehydrogenase(39kDa),CarbonicAnhydrase(28kDa),MyoglobinRed(19kDa),Lysozyme(14kDa) |
Overview:
HumanproteinZ(PZ)isasinglechain,vitaminK-dependantplasmaprotein(1,2).Analogouswiththemajorityofthecoagulationproteins,proteinZissynthesizedintheliver.Thematureproteincontains360aminoacids(4).BasedonaminoacidsequencehomologythedomainstructureissimilartothatofothervitaminK-dependantzymogenswhichinclude;factorVII,factorIX,factorX,andproteinC(3,4).TheN-terminalregioncontainsacarboxyglutamicacid(Gla)domainimportantinitsphospholipidmembranebindingABIlity(5).FollowingtheN-terminalGladomainaretwoEGFdomainsandaregionwhichconnectstoacatalytic-likedomain(3,4).TheC-terminalregionhasbeenshowntolackthe"typical"serineproteaseactivationsiteaswellastheHisandSerresiduesfromthecatalytictriad(3,4).Proteaseactivityhasnotbeendetectedineitherthefull-lengthproteinorcleavageproductsofproteinZ(2).FunctionallyproteinZhasbeenshowntobeadirectrequirementforthebindingofthrombintoendothelialphospholipids(6,7).ProteinZalsoservesasacofactorfortheinhibitionofcoagulationfactorXabyaplasmaserpincalledproteinZ-dependantproteaseinhibitor(ZPI)(8).InhibitionisdependantuponcomplexformationbetweenfactorXa-PZ-ZPIonthephospholipidsurface(8).
ThephysiologicalfunctionofproteinZisstillratherilldefined.Asisthecasewithothercoagulationproteinsandinhibitors,proteinZisconsumedduringdisseminatedintravascularcoagulation(DIC)(9).FurThermore,patientsdiagnosedwithaproteinZdeficiencypresentwithabnormalbleedingdiathesisduringandaftersurgicalevents(10).ThesefindingsprovidedirectevidenceastotheimportanceofproteinZinbloodcoagulation.
HumanproteinZispreparedfromfreshfrozenplasmasimilartotheproceduredescribedbyBrozeandMiletich(2).ThepurifiedproteinZissuppliedin50%(vol/vol)glycerol/H2Oandshouldbestoredat-20oC.PurityisassessedbySDS-PAGEanalysis.
Properties:
| Localization | Plasma | |||||
|---|---|---|---|---|---|---|
| Plasmaconcentration | 2.7µg/ml(11) | |||||
| Modeofaction | RequiredforthebindingofthrombintophospholipidsurfacesandforPZdependantinhibitionoffactorXa. | |||||
| Molecularweight | 62,000(2) | |||||
| Extinctioncoefficient |
| |||||
| Structure | Singlechain,(Mr=62,000),displaysstructuralsimilaritytoothervitaminK-dependantcoagulationfactorsbasedonsequencehomology,mostnotablyfactorX(3,4) |
