title: Macromolecular crowding explains overflow metabolism in cells.
abstract: Overflow metabolism is a metabolic phenotype of cells characterized by mixed oxidative phosphorylation (OxPhos) and fermentative glycolysis in the presence of oxygen. Recently, it was proposed that a combination of a protein allocation constraint and a higher proteome fraction cost of energy generation by OxPhos relative to fermentation form the basis of overflow metabolism in the bacterium, Escherichia coli. However, we argue that the existence of a maximum or optimal macromolecular density is another essential requirement. Here we re-evaluate our previous theory of overflow metabolism based on molecular crowding following the proteomic fractions formulation. We show that molecular crowding is a key factor in explaining the switch from OxPhos to overflow metabolism.
authors.affiliation: Beatson Institute for Cancer Research, Glasgow, UK.
authors.forename: Alexei
authors.initials: A
authors.lastname: Vazquez
authors.affiliation: Departments of Pathology and Computational &Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
authors.forename: Zoltán N
authors.initials: ZN
authors.lastname: Oltvai
mesh_terms: D000066949:Biobehavioral Sciences; D004926:Escherichia coli / Q000378:metabolism*; D006019:Glycolysis / Q000502:physiology*; D010085:Oxidative Phosphorylation