Expression and isotopic labelling of the potassium channel blocker ShK toxin as a thioredoxin fusion protein in bacteria

► ShK is a potent potassium channel blocker. ► A recombinant expression system for ShK has been established. ► Recombinant ShK is equipotent with synthetic ShK in a range of bioassays. ► Expression yield is maintained in minimal media suitable for isotopic labelling.