Synthesis of a GPI anchor module suitable for protein post-translational modification

Eukaryotic cell surface proteins are often modified by a glycosylphosphatidylinositol (GPI) anchor. More than 200 of these post-translationally altered proteins are presently known, a prominent example being the prion protein (PrP). Although the significance of the GPI anchor is well recognized, efforts to study its function are hampered due to its complex chemical nature, which combines hydrophilic glycosyl chains with hydrophobic lipid moieties. Here we describe a general method for the synthesis of a GPI-anchored peptide containing an N-terminal Cys. This module can be employed for the production of proteins containing a natural GPI anchor using expressed protein ligation.