Synthesis and characterisation of a multiphosphorylated phosphophoryn repeat motif; H-[Asp-(Ser(P))2]3-Asp-OH

Abstract

Protein phosphorylation is a critical mechanism in the regulation of cellular biochemical pathways and phosphopeptides can play an important role in determining function. However, the use of phosphopeptides especially multiphosphorylated peptides is hampered by their low abundance, difficulty in isolation from biological samples and in their chemical synthesis. Here we describe methodologies for the Fmoc synthesis, purification and mass spectral analysis of the multiphosphorylated sequence H-[Asp-(Ser(P))2] 3-Asp-OH from phosphophoryn a protein involved in dentine mineralization. Critical steps in the synthesis of phosphophoryn using Fmoc-Ser(PO3Bzl,H)-OH as the building block were double ac..