Isolation of Uridine 5′-Pyrophosphate Glucuronic Acid Pyrophosphorylase and Its Assay Using 32P-Pyrophosphate

Abstract
A procedure was devised to detect and assay UDP-glucuronic acid pyrophosphorylase [EC 2.7.7.aa] in plant extracts [Lilium longiflorum]. Substrates are UDP-glucuronic acid and 32P-pyrophosphate, and the 32P-UTP produced is selectively adsorbed to charcoal. The charcoal adsorption procedure is a modification of that used to determine 32P-ATP produced by ADP glucose pyrophosphorylase, and the modification greatly improves the retention of UTP.