EcotinsaredimericperiplasmicproteinsfromEscherichiacoliandrelatedGram-negativebacteriathathavebeenshowntobepotentandgeneralinhibitorsofmanytrypsin-foldserineproteasesofwidelyvaryingsubstratespecificity,whichbelongtoMEROPSpeptidasefamilyS1.Ecotinproteininhibitschymotrypsin,trypsin,elastases,factorX,kallikreinaswellasavarietyofotherproteasesandhasbeencharacterizedasanextremelypotentanticoagulantandreversIBLetight-bindinginhibitorofhumanfactorXa(FXa).Thepowerofinhibitionisnotlinkedtoaspecificproteasespecificity.Immobilizedecotinhasbeenusedtoaffinity-purifyrecombinanttrypsinogen,indicatingthatitmayalsobeusedtopurifyadditionalserineproteasezymogens.Comparedtootherserineproteaseinhibitorssuchasmembersoftheserpinfamily,thereactivesiteofecotinisMet104(P1).Phylogeneticanalysissuggestedthatecotinhasanexogenoustarget,possiblyneutrophilelastase.EcotinfromE.coli,Yersiniapestis,andPseudomonasaeruginosa,allspeciesthatencounterthemammalianimmunesystem,inhibitneutrophilelastasestronglywhileecotinfromtheplantpathogenPantoeacitreainhibitsneutrophilelastase1000-foldlesspotently.Ecotinsallpotentlyinhibitpancreaticdigestivepeptidasestrypsinandchymotrypsin,whileshowingmorevariableinhibitionofthebloodpeptidasesFactorXa,thrombin,andurokinase-typeplasminogenactivator.Ecotinissynthesizedasa162aminoacidprecursorwitha20aminoacidsignalpeptidenecessarytodirectittotheperiplasmicspace.Thematureprotein(residues21-162)isexpressedandpurified.
| Source | E.coli |
| Names | Ecotin,eco,eti |
| Accession# | P23827 |
| Formulation | Lyophilizedfroma0.2μMfilteredsolutionof20mMTris-HCl,300mMNaCl,pH8.5 |
| Shipping | Theproductisshippedatambienttemperature. |
| Reconstitution | Alwayscentrifugetubesbeforeopening.Donotmixbyvortexorpipetting. Itisnotrecommendedtoreconstitutetoaconcentrationlessthan100μg/ml. Dissolvethelyophilizedproteinin1XPBS. Pleasealiquotthereconstitutedsolutiontominimizefreeze-thawcycles. |
| Storage | Lyophilizedproteinshouldbestoredat<-20°C,thoughstableatroomtemperaturefor3weeks. Reconstitutedproteinsolutioncanbestoredat4-7°Cfor2-7days. Aliquotsofreconstitutedsamplesarestableat<-20°Cfor3months. |
| Purity | Greaterthan95%asdeterminedbySEC-HPLCandreducingSDS-PAGE. |
| Endotoxin | Lessthan0.1ng/μg(1IEU/μg). |
| AminoAcidSequence | AESVQPLEKIAPYPQAEKGMKRQVIQLTPQEDESTLKVELLIGQTLEVDCNLHRLGGKLENKTLEGWGYDYYVFDKVSSPVSTMMACPDGKKEKKFVTAYLGDAGMLRYNSKLPIVVYTPDNVDVKYRVWKAEEKIDNAVVRLEHHHHHH |
