Journal Article

Bacterial Toxicity of Potassium Tellurite: Unveiling an Ancient Enigma

Pérez, José M., Sandoval, Juan M., Fuentes, Derie E., Calderón, Iván L., Castro, Miguel E., Arenas, Felipe A., Pradenas, Gonzalo A., Elías, Alex O., Vásquez, Claudio C., Fuentes, Eugenia L.

2007

Overview

Biochemical, genetic, enzymatic and molecular approaches were used to demonstrate, for the first time, that tellurite (TeO(3) (2-)) toxicity in E. coli involves superoxide formation. This radical is derived, at least in part, from enzymatic TeO(3) (2-) reduction. This conclusion is supported by the following observations made in K(2)TeO(3)-treated E. coli BW25113: i) induction of the ibpA gene encoding for the small heat shock protein IbpA, which has been associated with resistance to superoxide, ii) increase of cytoplasmic reactive oxygen species (ROS) as determined with ROS-specific probe 2'7'-dichlorodihydrofluorescein diacetate (H(2)DCFDA), iii) increase of carbonyl content in cellular proteins, iv) increase in the generation of thiobarbituric acid-reactive substances (TBARs), v) inactivation of oxidative stress-sensitive [Fe-S] enzymes such as aconitase, vi) increase of superoxide dismutase (SOD) activity, vii) increase of sodA, sodB and soxS mRNA transcription, and viii) generation of superoxide radical during in vitro enzymatic reduction of potassium tellurite.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Aconitate Hydratase - antagonists & inhibitors / Bacteria / Bacterial Proteins - biosynthesis / Bacterial Proteins - genetics / Biochemistry / Carbonyl compounds / Carbonyls / Cloning / Cold Shock Proteins and Peptides / Deactivation / E coli / Enzymes / Escherichia coli / Escherichia coli - drug effects / Escherichia coli - genetics / Escherichia coli - metabolism / Escherichia coli Proteins - antagonists & inhibitors / Escherichia coli Proteins - biosynthesis / Escherichia coli Proteins - genetics / Fluoresceins - analysis / Gene Expression Regulation, Bacterial - drug effects / Genes / Heat shock proteins / Heat-Shock Proteins - biosynthesis / Heat-Shock Proteins - genetics / Inactivation / Laboratories / Microbiology / Molecular Biology / Oxidation-Reduction / Oxidative stress / Oxygen / Potassium / Potassium tellurite / Proteins / Pseudomonas / Reactive oxygen species / Reactive Oxygen Species - metabolism / Recombinant Fusion Proteins - biosynthesis / Recombinant Fusion Proteins - genetics / Reduction / RNA / RNA, Bacterial - biosynthesis / RNA, Messenger - biosynthesis / Saccharomyces cerevisiae / SoxS protein / Stress response / Superoxide dismutase / Superoxide Dismutase - biosynthesis / Superoxide Dismutase - genetics / Superoxides / Superoxides - metabolism / Tellurite / Tellurium - toxicity / Tellurium dioxide / Thiobarbituric acid / Thiobarbituric Acid Reactive Substances - analysis / Toxicity / Trans-Activators - biosynthesis / Trans-Activators - genetics / Transcription