title: Monounsaturated fatty acids are substrates for aldehyde generation in tellurite-exposed Escherichia coli.
abstract: Reactive oxygen species (ROS) damage macromolecules and cellular components in nearly all kinds of cells and often generate toxic intracellular byproducts. In this work, aldehyde generation derived from the Escherichia coli membrane oxidation as well as membrane fatty acid profiles, protein oxidation, and bacterial resistance to oxidative stress elicitors was evaluated. Studies included wild-type cells as well as cells exhibiting a modulated monounsaturated fatty acid (MUFA) ratio. The hydroxyaldehyde 4-hydroxy 2-nonenal was found to be most likely produced by E. coli, whose levels are dependent upon exposure to oxidative stress elicitors. Aldehyde amounts and markers of oxidative damage decreased upon exposure to E. coli containing low MUFA ratios, which was paralleled by a concomitant increase in resistance to ROS-generating compounds. MUFAs ratio, lipid peroxidation, and aldehyde generation were found to be directly related; that is, the lower the MUFAs ratio, the lower the peroxide and aldehyde generation levels. These results provide additional evidence about MUFAs being targets for membrane lipid oxidation and their relevance in aldehyde generation.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago de Chile, Chile.
authors.forename: Gonzalo A
authors.initials: GA
authors.lastname: Pradenas
authors.forename: Waldo A
authors.initials: WA
authors.lastname: Díaz-Vásquez
authors.forename: José M
authors.initials: JM
authors.lastname: Pérez-Donoso
authors.forename: Claudio C
authors.initials: CC
authors.lastname: Vásquez
mesh_terms: D000447:Aldehydes / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013691:Tellurium / Q000494:pharmacology*
chemical_list: D000447:Aldehydes; D005229:Fatty Acids, Monounsaturated; D008563:Membrane Lipids; D017382:Reactive Oxygen Species; C026660:tellurous acid; D013691:Tellurium