Cataloguenumber
CYT-205
Synonyms
IFNalpha2b,IFNA,INFA2,MGC125764,MGC125765.
Introduction
IFN-alphaisproducedbymacrophagesandhasantiviralactivities.IFNstimulatestheproductionoftwoenzymes:proteinkinaseandanoligoadenylatesynthetase.
Description
IFN-a2bHumanRecombinantproducedinE.Coliisasingle,non-glycosylated,polypeptidechaincontaining166aminoacidsandhavingamolecularmassof19400Dalton.ThedifferencebetweenIFNA2AandIFNA2Bisintheaminoacidpresentatposition23.IFN-alpha2ahasalysineatthatposition23whileIFN-alpha2bhasarginine.
TheIFN-alpha2bgenewasobtainedfromhumanleukocytes.
TheIFN-a2bispurifiedbyproprietarychromatographictechniques.
Source
PhysicalAppearance
Formulation
Solubility
ItisrecommendedtoreconstitutethelyophilizedIFN-alpha2binsterile18MΩ-cmH2Onotlessthan100µg/ml,whichcanthenbefurtherdilutedtootheraqueoussolutions.
StABIlity
LyophilizedIFNalthoughstableatroomtemperaturefor3weeks,shouldbestoreddesiccatedbelow-18°C.UponreconstitutionIFNalpha2bshouldbestoredat4°Cbetween2-7daysandforfutureusebelow-18°C.Forlongtermstorageitisrecommendedtoaddacarrierprotein(0.1%HSAorBSA).Pleasepreventfreeze-thawcycles.
Purity
Aminoacidsequence
MCDLPQTHSLGSRRTLMLLAQMRRISLFSCLKDRHDFGFPQEEFGNQFQKAETIPVLHEMIQQIFNLFSTKDSSAAWDETLLDKFYTELYQQLNDLEACVIQGVGVTETPLMKEDSILAVRKYFQRITLYLKEKKYSPCAWEVVRAEIMRSFSLSTNLQESLRSKE
BIOLOGicalActivity
Proteincontent
References
Title:IFN-βinducesapoptosisinhumanSH-SY5YneuroblastomacellsthroughactivationofJAK–STATsignalinganddown-regulationofPI3K/Aktpathway.Publication:Articlefirstpublishedonline:11NOV2010DOI:10.1111/j.1471-4159.2010.07046.x©2010TheAuthors.JournalofNeuRochemistry©2010InternationalSocietyforNeurochemistry.Link:http://onlinelibrary.wiley.com/doi/10.1111/j.1471-4159.2010.07046.x/full
Usage
SafetyDataSheet
SDS
Background
IFN-alphaformsareproducedbymonocytes/macrophages,lymphoblastoidcells,fibroblasts,andanumberofdifferentcelltypesfollowinginductionbyviruses,nucleicacids,glucocorticoidhormones,andlow-molecularweightsubstances(n-butyrate,5-bromodeoxyuridine).Atleast23differentvariantsofIFN-alphaareknown.Theindividualproteinshavemolecularmassesbetween19-26kDaandconsistofproteinswithlengthsof156-166and172aminoacids.AllIFN-alphasubtypespossessacommonconservedsequenceregionbetweenaminoacidpositions115-151whiletheamino-terminalendsarevariable.ManyIFN-alphasubtypesdifferintheirsequencesatonlyoneortwopositions.Naturallyoccurringvariantsalsoincludeproteinstruncatedby10aminoacidsatthecarboxy-terminalend.Disulfidebondsareformedbetweencysteinesatpositions1/98and29/138.Thedisulfidebond29/138isessentialforbiologicalactivitywhilethe1/98bondcanbereduceswithoutaffectingbiologicalactivity.AllIFN-alphaformscontainapotentialglycosylationsitebutmostsubtypesarenotglycosylated.IncontrasttoIFN-gammaIFN-alphaproteinsarestableatpH2.
Thereareatleast23differentIFN-alphagenes.Theyhavealengthof1-2kbandareclusteredonhumanchromosome9p22.Itisnotknownwhetherallthesegenesareexpressedfollowingstimulationofthecells.Insomecellsystemsexpressionofsomesubtypes(IFN-alpha-1,IFN-alpha-2,IFN-alpha-4)isstrongerthanthoseofothers.IFN-alphagenesdonotcontainintronsequencesfoundinmanyothereukaryoticgenes(seealso:geneexpression).BaseduponthestructurestwotypesofIFN-alphagenes,designatedclass1andII,aredistinguished.Theyencodeproteinsof156-166and172aminoacids,respectively.Deletionscovering9p22areobservedfrequentlyincellsoflymphoblastoidleukemias.ItisnotknowntodatewhetherthisisofsignificancewithrespecttoIFNexpression.
ThegeneencodingtheIFN-alphareceptormapstohumanchromosome21q22.1.IFN-alphaandIFN-betaarethoughttobindtothesameIFNbindingsubunitwhichisexpressedin100-5000copiesinIFN-alphasensitiveand-resistantcellsandisassociatedwithotherasyetunidentifiedproteins.TheIFN-omega(OmegaIFN)alsobindstotheIFN-alpha/IFN-betareceptor.AnotherreceptorexpressedonB-lymphocytesisidenticalwithCD21.ThisreceptoralsobindsEpstein-Barrvirusthroughitsgp350/220coatprotein.SignaltransductionmechanismselicitedafterbindingofIFN-alphatoitsreceptorsinvolvestyrosinephosphorylation(seealso:PTK;proteintyrosinekinase)ofvariousnon-receptortyrosinekinasesbelongingtotheJanuskinases.SolubleformsoftheIFN-alphareceptor,correspondingtotruncatedformsoftheextracellulardomainofthecellsurfaceIFN-alphareceptor,havebeenfoundinhumanserumandinnormalhumanurine.
AllknownsubtypesofIFN-alphashowthesameantiviralantiparasitic,antiproliferativeactivitiesinsuitablebioassaysalthoughtheymaydifferinrelativeactivities.HumanIFN-alphaisalsoapotentantiviralsubstanceinmurine,porcine,andbovinecellsystems.HumanIFN-alphaislessactiveinrodentcells.Site-directedmutagenesistechniqueshavebeenusedtocreatesomevariantsofcertainsubtypes(IFN-alpha-2)thatdisplayapproximately100-foldenhancedantiviralactivitiesinmousecells.
