Biosynthesis of peptide fragments of eukaryotic GPCRs in Escherichia coli by directing expression into inclusion bodies.

Biosynthesis of peptides in heterologous systems is often a prerequisite to biophysical analyses. Large amounts of peptides, in particular portions of membrane proteins, are needed to optimize conditions for secondary and tertiary structure analysis. Chemical synthesis of these peptides is limited by their high hydrophobicity and also due to the need to incorporate isotopic labels for high resolution NMR analysis. In this protocol, we describe a method for the heterologous expression and purification of unlabeled and isotopically labeled peptide fragments of Ste2p, an integral membrane G protein-coupled receptor. (c) 2010 European Peptide Society and John Wiley & Sons, Ltd.