TY - JOUR
T1 - Bacterial toxicity of potassium tellurite
T2 - Unveiling an ancient enigma
AU - Pérez, José M.
AU - Calderón, Iván L.
AU - Arenas, Felipe A.
AU - Fuentes, Derie E.
AU - Pradenas, Gonzalo A.
AU - Fuentes, Eugenia L.
AU - Sandoval, Juan M.
AU - Castro, Miguel E.
AU - Elías, Alex O.
AU - Vásquez, Claudio C.
PY - 2007/2/14
Y1 - 2007/2/14
N2 - Biochemical, genetic, enzymatic and molecular approaches were used to demonstrate, for the first time, that tellurite (TeO3 2-) toxicity in E. coli involves superoxide formation. This radical is derived, at least in part, from enzymatic TeO32- reduction. This conclusion is supported by the following observations made in K2TeO3-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 (H2DCFDA), 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.
AB - Biochemical, genetic, enzymatic and molecular approaches were used to demonstrate, for the first time, that tellurite (TeO3 2-) toxicity in E. coli involves superoxide formation. This radical is derived, at least in part, from enzymatic TeO32- reduction. This conclusion is supported by the following observations made in K2TeO3-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 (H2DCFDA), 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.
UR - http://www.scopus.com/inward/record.url?scp=35148858536&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0000211
DO - 10.1371/journal.pone.0000211
M3 - Article
C2 - 17299591
AN - SCOPUS:35148858536
SN - 1932-6203
VL - 2
JO - PLoS ONE
JF - PLoS ONE
IS - 2
M1 - e211
ER -