Type
Recombinant
Description
IL-21 isapleiotropiccytokineproducedbyCD4+Tcellsinresponsetoantigenicstimulation.Itsactiongenerallyenhancesantigen-specificresponsesofimmunecells.TheBIOLOGicaleffectsofIL-21 include:inducingthedifferentiationofT-cell-stimulatedB-cellsintoplasmacellsandmemoryB-cells;thestimulationofIgGproductioninconjunctionwithIL-4;andtheinductionofapoptoticeffectsinnaïveB-cellsandstimulatedB-cellsintheabsenceofT-cellsignaling.Additionally,IL-21 promotestheanti-tumoractivityofCD8+T-cellsandNKcells.IL-21 exertsitseffectthroughbindingtoaspecifictypeI cytokinereceptor,IL-21R,whichalsocontainstheγchain(γc)foundinothercytokinereceptors,includingIL-2,IL-4,IL-7,IL-9 andIL-15. TheIL-21/IL-21Rinteractiontriggersacascadeofevents,whichincludesactivationofthetyrosinekinasesJAK1andJAK3,followedbyactivationofthetranscriptionfactorsSTAT1andSTAT3.RecombinantHumanIL-21 isa15.4 kDaproteinconsistingof132 aminoacidresidues.
AminoAcidSequence
MQDRHMIRMRQLIDIVDQLKNYVNDLVPEFLPAPEDVETNCEWSAFSCFQKAQLKSANTGNNERIINVSIKKLKRKPPSTNAGRRQKHRLTCPSCDSYEKKPPKEFLERFKSLLQKMIHQHLSSRTHGSEDS
Source
E.coli
Purity
98%
BiologicalActivity
Assay#1:DeterminedbyitsABIlitytoproliferateactivatedBcells.Assay#2:DeterminedbyitsabilitytostimulatetheproliferationofhumanANBL-6 cells.TheexpectedED50 is≤0.5 ng/ml,correspondingtoaspecificactivityof≥2 x106 units/mg.
Endotoxin
Endotoxinlevelis<0.1 ng/μgofprotein(<1EU/μg).
Reconstitution
Centrifugethevialpriortoopening.Reconstituteinwatertoaconcentrationof0.1–1.0 mg/ml.Donotvortex.Thissolutioncanbestoredat2–8°Cforupto1 week.Forextendedstorage,itisrecommendedtofurtherdiluteinabuffercontainingacarrierprotein(example0.1%BSA)andstoreinworkingaliquotsat –20°Cto –80°C.
Storage/Expiration
–20°C