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Inactivation-reactivation of aconitase in Escherichia coli. A sensitive measure of superoxide radical.
J Biol Chem. 1992 May 05; 267(13):8757-63.JB

Abstract

The rapid inactivation of aconitase by O2-, previously seen to occur in vitro, was explored in vivo. A fraction of the aconitase in growing, aerobic, Escherichia coli is inactive at any instant but can be activated by imposition of anaerobic conditions. This reactivation occurred in the absence of protein synthesis and was inhibited by the ferrous chelator alpha,alpha'-dipyridyl. This fraction of inactive, but activatable, aconitase was increased by augmenting O2- production with paraquat, decreased by elevation of superoxide dismutase, and increased by inhibiting reactivation with alpha,alpha'-dipyridyl. The balance between inactive and active aconitase thus represented a pseudoequilibrium between inactivation by O2- and reactivation by restoration of Fe(II), and it provided, for the first time, a measure of the steady-state concentration of O2- within E. coli. On this basis, [O2-] was estimated to be approximately 20-40 pM in aerobic log phase E. coli containing wild type levels of superoxide dismutase and approximately 300 pM in a mutant strain lacking superoxide dismutase.

Authors+Show Affiliations

Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

1315737

Citation

Gardner, P R., and I Fridovich. "Inactivation-reactivation of Aconitase in Escherichia Coli. a Sensitive Measure of Superoxide Radical." The Journal of Biological Chemistry, vol. 267, no. 13, 1992, pp. 8757-63.
Gardner PR, Fridovich I. Inactivation-reactivation of aconitase in Escherichia coli. A sensitive measure of superoxide radical. J Biol Chem. 1992;267(13):8757-63.
Gardner, P. R., & Fridovich, I. (1992). Inactivation-reactivation of aconitase in Escherichia coli. A sensitive measure of superoxide radical. The Journal of Biological Chemistry, 267(13), 8757-63.
Gardner PR, Fridovich I. Inactivation-reactivation of Aconitase in Escherichia Coli. a Sensitive Measure of Superoxide Radical. J Biol Chem. 1992 May 5;267(13):8757-63. PubMed PMID: 1315737.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Inactivation-reactivation of aconitase in Escherichia coli. A sensitive measure of superoxide radical. AU - Gardner,P R, AU - Fridovich,I, PY - 1992/5/5/pubmed PY - 1992/5/5/medline PY - 1992/5/5/entrez SP - 8757 EP - 63 JF - The Journal of biological chemistry JO - J Biol Chem VL - 267 IS - 13 N2 - The rapid inactivation of aconitase by O2-, previously seen to occur in vitro, was explored in vivo. A fraction of the aconitase in growing, aerobic, Escherichia coli is inactive at any instant but can be activated by imposition of anaerobic conditions. This reactivation occurred in the absence of protein synthesis and was inhibited by the ferrous chelator alpha,alpha'-dipyridyl. This fraction of inactive, but activatable, aconitase was increased by augmenting O2- production with paraquat, decreased by elevation of superoxide dismutase, and increased by inhibiting reactivation with alpha,alpha'-dipyridyl. The balance between inactive and active aconitase thus represented a pseudoequilibrium between inactivation by O2- and reactivation by restoration of Fe(II), and it provided, for the first time, a measure of the steady-state concentration of O2- within E. coli. On this basis, [O2-] was estimated to be approximately 20-40 pM in aerobic log phase E. coli containing wild type levels of superoxide dismutase and approximately 300 pM in a mutant strain lacking superoxide dismutase. SN - 0021-9258 UR - https://www.unboundmedicine.com/medline/citation/1315737/Inactivation_reactivation_of_aconitase_in_Escherichia_coli__A_sensitive_measure_of_superoxide_radical_ DB - PRIME DP - Unbound Medicine ER -