Use of Zn—pyrophosphatase in the high-performance liquid chromatographic analysis of cell extracts containing 32P-labelled inositol phosphates

A simple method is described for eliminating the interference of pyrophosphate and pyrophosphorylated nucleosides in the high-performance liquid chromatographic determination of inositol 1,3,4-triphosphate and inositol 1,4,5-triphosphate of 32P-labelled extracts of cells. Treatment of the extract with pyrophosphatase, but substituting Zn2+ for Mg2+ as the cofactor, converts all nucleoside triphosphates and pyrophosphate to their di- and monoesters. Such change shifts their position in the elution profile, allowing a clear identification and quantification of the inositol phosphates. Typical overall recoveries near 80% or higher of added markers.