Open AccessUnderstanding the regulation of aspartate metabolism using a model based on measured kinetic parameters
Author(s) -
Curien Gilles,
Bastien Olivier,
RobertGenthon Mylène,
CornishBowden Athel,
Cárdenas María Luz,
Dumas Renaud
Publication year - 2009
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.1038/msb.2009.29
Subject(s) - allosteric regulation , function (biology) , flux (metallurgy) , biological system , arabidopsis , identification (biology) , threonine , computational biology , enzyme , biochemistry , biology , chemistry , serine , microbiology and biotechnology , ecology , gene , organic chemistry , mutant
The aspartate‐derived amino‐acid pathway from plants is well suited for analysing the function of the allosteric network of interactions in branched pathways. For this purpose, a detailed kinetic model of the system in the plant model Arabidopsis was constructed on the basis of in vitro kinetic measurements. The data, assembled into a mathematical model, reproduce in vivo measurements and also provide non‐intuitive predictions. A crucial result is the identification of allosteric interactions whose function is not to couple demand and supply but to maintain a high independence between fluxes in competing pathways. In addition, the model shows that enzyme isoforms are not functionally redundant, because they contribute unequally to the flux and its regulation. Another result is the identification of the threonine concentration as the most sensitive variable in the system, suggesting a regulatory role for threonine at a higher level of integration.