| Formulation | 20mMTris,150mMNaCl,pH7.4 |
| MolecularWeight | |
| Storage | -80°C |
| Purity | >95%bySDS-PAGE |
| Compound | |
| Assay | aPTTassay |
| ShelfLife(properlystored) | 12months |
| ChemicalFormula |
ThegraphillustratestheeffectofaddedCTIonthePTandaPTTofnormalhumanplasma.CTIwasaddedtonormalpooledhumanplasmatovariousfinalconcentrations,andthemixtureswereallowedtoincubateforabriefperiodonicepriortoconductingtheassays.ThePTremainsunaffectedwhiletheaPTTdoubleswiththeadditionofapproximately60microgramsofCTIpermlofplasma.
SampleGelInformation:
| Gel | Novex4-12%Bis-Tris |
|---|---|
| Load | CornTrypsinInhibitor,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:
PurifiedCTI
Corntrypsininhibitor(CTI)isasmallproteinthatislocalizedinthekernelsofmostspeciesofcorn.CTIisnotonlyaninhibitoroftrypsin,butisalsoaspecifichumanfactorXIIainhibitorwhentestedinbloodclottingexperiments(1-6).Theinhibitorformsaone-to-onecomplexwitheithertrypsinorfactorXIIa,andwhenaddedtoplasma,prolongstheactivatedpartialthromboplastintimewithoutaffectingthePTassay(6).ThespecificityforfactorXIIamakestheinhibitorusefulforthesegregationandstudyoftissuefactor(TF)dependentcoagulationreactions(6).
TheuseofCTItostudyTF-dependentreactionshasbeendocumentedinliterature(6,8-10).StudiesindicatethatsuppressionofthecontactpathwayofcoagulationisessentialwhenattemptingtoperformTF-dependentassaysinwholebloodorplasmasamples.TheadditionofCTIatthepointofsamplecollectionpreventsactivationofthecontactpathwayduringsubsequentsampleprocessingsteps,thusreducingin-vitroartifact.ThemostcommonuseofCTIisassociatedwiththrombingenerationassayswhenattemptingtoworkatlowTFconcentrations.HTI’sCTIproductisperformancetestedforthisspecificapplication.
Theproteiniscomprisedof112aminoacidswhichyieldsacalculatedmolecularweightof12,028(7).Thecalculatedmolecularweightandthatwhichhasbeendeterminedbysedimentationequilibriumanalysesofthepurifiedprotein(12,500)areingoodagreement(3).AcomparisonoftheaminoacidsequenceofCTItothatofothertrypsinorserineproteaseinhibitorsrevealslittleornosimilarities(7).
CTIispurifiedusingacombinationofpublishedprocedures(3,4).Tobeginthepurificationprocess,CTIisextractedfromthekernelsoffreshsweetcornintoaphysiologicbuffer.Theextractisthende-fattedusingacetone,andtheproteinisfurtherpurifiedbyemployinggelfiltrationandion-exchangechromatography.ThefinalCTIpreparationappearsasasinglebandbySDS-PAGEanalysesunderbothreducingandnon-reducingconditions.
PreparationsofCTIaretestedfortheABIlitytoprolongtheaPTTassaywithoutaffectingthePTassay.ThespecificactivityofeachlotofCTIisdetermined,andoneunitisdefinedastheamountofCTIrequiredtodoubletheaPTTofnormalhumanplasma.
PurifiedCTIisformulatedin20mMTris,0.15MNaCl,pH7.4andshouldbestoredfrozenat-20°Corcolder.
BloodCollectionTubes
TosimplifytheprocessofcollectingsampleswithaddedCTI,HTIhasdevelopedbloodcollectiontubescontainingCTI.Thesetubes(ourSCAT-27line)simplifytheprocessofconductingTF-dependentstudiesbyallowingyoutodrawblooddirectlyontoananticoagulantcontainingCTI.YoumaychoosetouseourstandardCTI/Citrateformulation(11mMCitrate,50ug/mLCTI)oryoumaycreateyourowncustomformulation.HTI’sbloodcollectiontubesarenotsterileandaremanufacturedandsoldforresearchuseonly.Threestandardsizesareavailablealthoughcustomsizescanbemanufacturedforyou.
SCAT-27-4.5/5-5mLtube
SCAT-27-2.7/5-3mLtube
SCAT-27-1.8/5-2mLtube
Properties:
| Localization | CornKernals | |||||
|---|---|---|---|---|---|---|
| Modeofaction | formsaone-to-onecomplexwitheithertrypsinorfactorXIIaandinhibitstheirrespectivecatalyticactivity. | |||||
| Molecularweight | 12,500(3) | |||||
| Extinctioncoefficient |
| |||||
| Structure | singlechainproteincomprisedof112aminoacids(3,7) |
