BackgroundInformation | His-Tagisaseriesofatleast6histidineresiduesusedasatagmotifattheN-orC-terminusofrecombinantproteins.Therelativelysmallsizeofthistagvs.othercommonlyusedtagssuchasGST(30kDa)makesitlesslikelytointerferewithtargetproteinstructureorfunction.Itssmallsizealsomakesitmoresuitableforuseunderdenaturingconditions.Histagsaremostoftenusedforaffinitypurificationandbindingassays.Histagsbindtonickelorcobaltionswithhighaffinity,andthisinteractionwithmetalionsisthebasisofmanyhis-tagbasedaffinitymedia.TheHisTagepitopeiswidelyusedtodetectexpressionofrecombinantproteinsinbacterial,yeast,insect,andmammaliansystems. |