Scalable Chemoenzymatic Synthesis of Inositol Pyrophosphates.

The inositol pyrophosphates (PP-InsPs) are an important group of cellular messengers that influence a broad range of biological processes. To elucidate the functions of these high-energy metabolites at the biochemical level, access to the purified molecules is required. Here, a robust and scalable strategy for the synthesis of various PP-InsPs [5PP-InsP5, 1PP-InsP5, and 1,5(PP)2-InsP4] is reported, relying on the highly active inositol hexakisphosphate kinase A from Entamoeba histolytica and the kinase domain of human diphosphoinositol pentakisphosphate kinase 2. A facile purification procedure using precipitation with Mg2+ ions and an optional strong anion exchange chromatography on an FPLC system afforded PP-InsPs in high purity. Furthermore, the newly developed protocol could be applied to simplify the synthesis of radiolabeled 5PP-InsP5-β32P, which is a valuable tool for studying protein pyrophosphorylation. The chemoenzymatic method for obtaining PP-InsPs is readily amenable to both chemists and biologists and will thus foster future research on the multiple signaling functions of PP-InsP molecules.