Recombinant expression of soluble murine prion protein for C-terminal modification

Abstract

Membrane attachment of prion protein (PrP) via its glycosylphosphatidylinositol (GPI) anchor plays a key role during conversion of cellular PrPC into its pathogenic isoform PrPSc. Strategies to access homogenous lipidated PrP via expressed protein ligation (EPL) are required to fully decipher the effect of membrane attachment. Such strategies suffer from insoluble expression of PrP-intein fusion constructs and low folding efficiencies that severely limit the available amount of homogeneous lipidated PrP. Here, we describe an alternative method for expression of soluble PrP-intein fusion proteins in Escherichiacoli that provides access to natively folded PrP ready to use in EPL.