title: Measurement of the inorganic pyrophosphate in tissues of Pisum sativum L.
abstract: Purified pyrophosphate: fructose 6-phosphate 1-phosphotransferase (EC 2.7.1.90) was used to measure the inorganic pyrophosphate in unfractionated extracts of tissues of Pisum sativum L. The fructose 1,6-bisphosphate produced by the above enzyme was measured by coupling to NADH oxidation via aldolase (EC 4.1.2.13), triosephosphate isomerase (EC 5.3.1.1) and glycerol-3-phosphate dehydrogenase (EC 1.1.1.8). Amounts of pyrophosphate as low as 1 nmol could be measured. The contents of pyrophosphate in the developing embryo of pea, and in the apical 2 cm of the roots, were appreciable; 9.4 and 8.9 nmol g(-1) fresh weight, respectively. The possibility that pyrophosphate acts in vivo as an energy source for pyrophosphate: fructose 6-phosphate 1-phosphotransferase and for UDPglucose pyrophosphorylase (EC 2.7.7.9) is considered.
authors.affiliation: Botany School, University of Cambridge, Downing Street, CB2 3EA, Cambridge, UK.
authors.forename: J
authors.initials: J
authors.lastname: Edwards
authors.forename: T A
authors.initials: TA
authors.lastname: Rees
authors.forename: P M
authors.initials: PM
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Morrell