title: Bidirectionality and compartmentation of metabolic fluxes are revealed in the dynamics of isotopomer networks.
abstract: Isotope labeling is one of the few methods of revealing the in vivo bidirectionality and compartmentalization of metabolic fluxes within metabolic networks. We argue that a shift from steady state to dynamic isotopomer analysis is required to deal with these cellular complexities and provide a review of dynamic studies of compartmentalized energy fluxes in eukaryotic cells including cardiac muscle, plants, and astrocytes. Knowledge of complex metabolic behaviour on a molecular level is prerequisite for the intelligent design of genetically modified organisms able to realize their potential of revolutionizing food, energy, and pharmaceutical production. We describe techniques to explore the bidirectionality and compartmentalization of metabolic fluxes using information contained in the isotopic transient, and discuss the integration of kinetic models with MFA. The flux parameters of an example metabolic network were optimized to examine the compartmentalization of metabolites and and the bidirectionality of fluxes in the TCA cycle of Saccharomyces uvarum for steady-state respiratory growth.
authors.affiliation: Laboratory of Systems Biology, Institute of Cybernetics, Tallinn University of Technology, Akadeemia 21, 12618 Tallinn, Estonia.
authors.forename: David W
authors.initials: DW
authors.lastname: Schryer
authors.affiliation: Laboratory of Systems Biology, Institute of Cybernetics, Tallinn University of Technology, Akadeemia 21, 12618 Tallinn, Estonia.
authors.forename: Pearu
authors.initials: P
authors.lastname: Peterson
authors.affiliation: Department of Food Processing, Tallinn University of Technology, Ehitajate 5, 19086 Tallinn, Estonia.
authors.forename: Toomas
authors.initials: T
authors.lastname: Paalme
authors.affiliation: Laboratory of Systems Biology, Institute of Cybernetics, Tallinn University of Technology, Akadeemia 21, 12618 Tallinn, Estonia.
authors.forename: Marko
authors.initials: M
authors.lastname: Vendelin
mesh_terms: D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D002952:Citric Acid Cycle; D007553:Isotope Labeling; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D008962:Models, Theoretical; D012440:Saccharomyces / Q000378:metabolism
chemical_list: D000255:Adenosine Triphosphate