kcat/Km ≤5×10^6M^−1×s^−1: O2− concentration in wildtype cell 10^−10M
||Bacteria Escherichia coli
||Imlay JA. The molecular mechanisms and physiological consequences of oxidative stress: lessons from a model bacterium. Nat Rev Microbiol. 2013 Jul11(7):443-54. doi: 10.1038/nrmicro3032. p.449 left column 2nd paragraphPubMed ID23712352
|| Flint, D. H., Tuminello, J. F. & Emptage, M. H. The inactivation of Fe-S cluster containing hydro-lyases by superoxide. J. Biol. Chem. 268, 22369–22376 (1993).PubMed ID8226748
||Primary source abstract: "[Investigators] report in this paper that highly purified Escherichia coli dihydroxy-acid dehydratase, fumarase A, fumarase B, and mammalian aconitase are inactivated by O2- with second order rate constants in the range of 10^(6) to 10^(7) M^-1×s^-1."
||P.449 left column 2nd paragraph: "The rate constant for Fe–S cluster damage by O2− (up to 5×10^6M^−1×s^−1 (primary source)) is so high that even in wild-type cells, in which abundant SODs [superoxide dismutase] keep O2− at a miniscule 10^−10 M concentration, the half-time for enzyme damage is ~20 minutes (Box 2)."