A Colorimetric Method for the Assay of Adenosine 5'-diphosphate (ADP)-glucose Pyrophosphorylase

C. FUSARI, A.M. DEMONTE, C.M. FIGUEROA, M. ALEANZI, A.A. IGLESIAS

ANALYTICAL BIOCHEMISTRY

Academic Press

Año: 2006 vol. 352 p. 145 - 147

0003-2697

ADP-glucose pyrophosphorylase (ADPGlcPPase, ATP:a-D-glucose-1-P adenylyltransferase, EC 2.7.7.27) is the regulatory enzyme for the synthesis of glycogen and starch in bacteria and plants, respectively [1,2]. Most of the ADPGlcPPases so far characterized are allostericallyregulated by key metabolites of the main route of carbon use in the corresponding organism [3]. They were grouped into nine classes based on the specificity for allosteric effector [1,2]. With the requirement of a divalent metal ion (Mg2+), the enzyme catalyzes the reaction: ATP þ Glc-1P () ADPGlc þ PPi. ð1Þ Although freely reversible in vitro, the reaction occurs irreversibly toward synthesis of ADPGlc in vivo after the hydrolysis of PPi by inorganic pyrophosphatase and the sugar nucleotide use for polysaccharide synthesis [1?3]. The reaction was first identified in soybean [4] and later found in different bacteria, green algae, and higher plants [1?3].