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Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes

Metabolic flux analysis (MFA) is an increasingly important tool to study metabolism quantitatively. Unlike the concentrations of metabolites, the fluxes, which are the rates at which intracellular metabolites interconvert, are not directly measurable. MFA uses stable isotope labeled tracers to revea...

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Autores principales: Wang, Yujue, Wondisford, Fredric E., Song, Chi, Zhang, Teng, Su, Xiaoyang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7694648/
https://www.ncbi.nlm.nih.gov/pubmed/33172051
http://dx.doi.org/10.3390/metabo10110447
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author Wang, Yujue
Wondisford, Fredric E.
Song, Chi
Zhang, Teng
Su, Xiaoyang
author_facet Wang, Yujue
Wondisford, Fredric E.
Song, Chi
Zhang, Teng
Su, Xiaoyang
author_sort Wang, Yujue
collection PubMed
description Metabolic flux analysis (MFA) is an increasingly important tool to study metabolism quantitatively. Unlike the concentrations of metabolites, the fluxes, which are the rates at which intracellular metabolites interconvert, are not directly measurable. MFA uses stable isotope labeled tracers to reveal information related to the fluxes. The conceptual idea of MFA is that in tracer experiments the isotope labeling patterns of intracellular metabolites are determined by the fluxes, therefore by measuring the labeling patterns we can infer the fluxes in the network. In this review, we will discuss the basic concept of MFA using a simplified upper glycolysis network as an example. We will show how the fluxes are reflected in the isotope labeling patterns. The central idea we wish to deliver is that under metabolic and isotopic steady-state the labeling pattern of a metabolite is the flux-weighted average of the substrates’ labeling patterns. As a result, MFA can tell the relative contributions of converging metabolic pathways only when these pathways make substrates in different labeling patterns for the shared product. This is the fundamental principle guiding the design of isotope labeling experiment for MFA including tracer selection. In addition, we will also discuss the basic biochemical assumptions of MFA, and we will show the flux-solving procedure and result evaluation. Finally, we will highlight the link between isotopically stationary and nonstationary flux analysis.
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spelling pubmed-76946482020-11-28 Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes Wang, Yujue Wondisford, Fredric E. Song, Chi Zhang, Teng Su, Xiaoyang Metabolites Review Metabolic flux analysis (MFA) is an increasingly important tool to study metabolism quantitatively. Unlike the concentrations of metabolites, the fluxes, which are the rates at which intracellular metabolites interconvert, are not directly measurable. MFA uses stable isotope labeled tracers to reveal information related to the fluxes. The conceptual idea of MFA is that in tracer experiments the isotope labeling patterns of intracellular metabolites are determined by the fluxes, therefore by measuring the labeling patterns we can infer the fluxes in the network. In this review, we will discuss the basic concept of MFA using a simplified upper glycolysis network as an example. We will show how the fluxes are reflected in the isotope labeling patterns. The central idea we wish to deliver is that under metabolic and isotopic steady-state the labeling pattern of a metabolite is the flux-weighted average of the substrates’ labeling patterns. As a result, MFA can tell the relative contributions of converging metabolic pathways only when these pathways make substrates in different labeling patterns for the shared product. This is the fundamental principle guiding the design of isotope labeling experiment for MFA including tracer selection. In addition, we will also discuss the basic biochemical assumptions of MFA, and we will show the flux-solving procedure and result evaluation. Finally, we will highlight the link between isotopically stationary and nonstationary flux analysis. MDPI 2020-11-06 /pmc/articles/PMC7694648/ /pubmed/33172051 http://dx.doi.org/10.3390/metabo10110447 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Review
Wang, Yujue
Wondisford, Fredric E.
Song, Chi
Zhang, Teng
Su, Xiaoyang
Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes
title Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes
title_full Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes
title_fullStr Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes
title_full_unstemmed Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes
title_short Metabolic Flux Analysis—Linking Isotope Labeling and Metabolic Fluxes
title_sort metabolic flux analysis—linking isotope labeling and metabolic fluxes
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7694648/
https://www.ncbi.nlm.nih.gov/pubmed/33172051
http://dx.doi.org/10.3390/metabo10110447
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