Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis

A distinct phosphodiesterasic activity (EC 3.1.4) was found in both mono- and dicotyledonous plants that catalyzes the hydrolytic breakdown of ADPglucose (ADPG) to produce equimolar amounts of glucose-1-phosphate and AMP. The enzyme responsible for this activity, referred to as ADPG pyrophosphatase...

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Autores: Rodríguez López, Milagros, Baroja Fernández, Edurne, Zandueta Criado, Aitor, Pozueta Romero, Javier
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/31888
Acceso en línea:https://hdl.handle.net/2454/31888
Access Level:acceso abierto
Palabra clave:ADPG pyrophosphatase
Phosphodiesterase
Starch biosynthesis
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spelling Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesisRodríguez López, MilagrosBaroja Fernández, EdurneZandueta Criado, AitorPozueta Romero, JavierADPG pyrophosphatasePhosphodiesteraseStarch biosynthesisA distinct phosphodiesterasic activity (EC 3.1.4) was found in both mono- and dicotyledonous plants that catalyzes the hydrolytic breakdown of ADPglucose (ADPG) to produce equimolar amounts of glucose-1-phosphate and AMP. The enzyme responsible for this activity, referred to as ADPG pyrophosphatase (AGPPase), was purified over 1,100-fold from barley leaves and subjected to biochemical characterization. The calculated Keq* (modified equilibrium constant) value for the ADPG hydrolytic reaction at pH 7.0 and 25°C is 110, and its standard-state free-energy change value (DG*) is 22.9 kcalymol (1 kcal 5 4.18 kJ). Kinetic analyses showed that, although AGPPase can hydrolyze several low-molecular weight phosphodiester bond-containing compounds, ADPG proved to be the best substrate (Km 5 0.5 mM). Pi and phosphorylated compounds such as 3-phosphoglycerate, PPi, ATP, ADP, NADP1, and AMP are inhibitors of AGPPase. Subcellular localization studies revealed that AGPPase is localized exclusively in the plastidial compartment of cultured cells of sycamore (Acer pseudoplatanus L.), whereas it occurs both inside and outside the plastid in barley endosperm. In this paper, evidence is presented that shows that AGPPase, whose activity declines concomitantly with the accumulation of starch during development of sink organs, competes with starch synthase (ADPG:1,4-a-D-glucan 4-a- D-glucosyltransferase; EC 2.4.1.21) for ADPG, thus markedly blocking the starch biosynthesis.National Academy of SciencesIdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua2000info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2454/31888reponame:Academica-e. Repositorio Institucional de la Universidad Pública de Navarrainstname:Universidad Pública de NavarraInglés© The National Academy of Sciencesinfo:eu-repo/semantics/openAccessoai:academica-e.unavarra.es:2454/318882026-06-17T12:41:47Z
dc.title.none.fl_str_mv Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
title Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
spellingShingle Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
Rodríguez López, Milagros
ADPG pyrophosphatase
Phosphodiesterase
Starch biosynthesis
title_short Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
title_full Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
title_fullStr Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
title_full_unstemmed Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
title_sort Adenosine diphosphate glucose pyrophosphatase: a plastidial phosphodiesterase that prevents starch biosynthesis
dc.creator.none.fl_str_mv Rodríguez López, Milagros
Baroja Fernández, Edurne
Zandueta Criado, Aitor
Pozueta Romero, Javier
author Rodríguez López, Milagros
author_facet Rodríguez López, Milagros
Baroja Fernández, Edurne
Zandueta Criado, Aitor
Pozueta Romero, Javier
author_role author
author2 Baroja Fernández, Edurne
Zandueta Criado, Aitor
Pozueta Romero, Javier
author2_role author
author
author
dc.contributor.none.fl_str_mv IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
dc.subject.none.fl_str_mv ADPG pyrophosphatase
Phosphodiesterase
Starch biosynthesis
topic ADPG pyrophosphatase
Phosphodiesterase
Starch biosynthesis
description A distinct phosphodiesterasic activity (EC 3.1.4) was found in both mono- and dicotyledonous plants that catalyzes the hydrolytic breakdown of ADPglucose (ADPG) to produce equimolar amounts of glucose-1-phosphate and AMP. The enzyme responsible for this activity, referred to as ADPG pyrophosphatase (AGPPase), was purified over 1,100-fold from barley leaves and subjected to biochemical characterization. The calculated Keq* (modified equilibrium constant) value for the ADPG hydrolytic reaction at pH 7.0 and 25°C is 110, and its standard-state free-energy change value (DG*) is 22.9 kcalymol (1 kcal 5 4.18 kJ). Kinetic analyses showed that, although AGPPase can hydrolyze several low-molecular weight phosphodiester bond-containing compounds, ADPG proved to be the best substrate (Km 5 0.5 mM). Pi and phosphorylated compounds such as 3-phosphoglycerate, PPi, ATP, ADP, NADP1, and AMP are inhibitors of AGPPase. Subcellular localization studies revealed that AGPPase is localized exclusively in the plastidial compartment of cultured cells of sycamore (Acer pseudoplatanus L.), whereas it occurs both inside and outside the plastid in barley endosperm. In this paper, evidence is presented that shows that AGPPase, whose activity declines concomitantly with the accumulation of starch during development of sink organs, competes with starch synthase (ADPG:1,4-a-D-glucan 4-a- D-glucosyltransferase; EC 2.4.1.21) for ADPG, thus markedly blocking the starch biosynthesis.
publishDate 2000
dc.date.none.fl_str_mv 2000
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2454/31888
url https://hdl.handle.net/2454/31888
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv © The National Academy of Sciences
info:eu-repo/semantics/openAccess
rights_invalid_str_mv © The National Academy of Sciences
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv National Academy of Sciences
publisher.none.fl_str_mv National Academy of Sciences
dc.source.none.fl_str_mv reponame:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
instname:Universidad Pública de Navarra
instname_str Universidad Pública de Navarra
reponame_str Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
collection Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
repository.name.fl_str_mv
repository.mail.fl_str_mv
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