Oxidizing intermediates in the reaction of ferrous EDTA with hydrogen peroxide. Reactions with organic molecules and ferrocytochrome c.
نویسندگان
چکیده
The reaction between hydrogen peroxide and ferrous EDTA generates an oxidizing intermediate (I1) which is not the hydroxyl radical. It oxidizes ferrocytochrome c and also reacts with hydrogen peroxide (k5 = 3.2 X 10(3) M-1 S-1) to form a second oxidizing transient (I2). I1 is not scavenged by t-butyl alcohol whereas I2 is. I1 is found to be significantly less reactive than the hydroxyl radical toward benzoate ion, t-butyl alcohol, acetate ion, arginine, and serine, but is scavenged by compounds with readily oxidizable functional groups such as ethanol and isopropyl alcohol. This indicates that I1 does not undergo the characteristic reactions of the hydroxyl radical but shows a pattern of reactivity more associated with a metal ion oxidant like a ferryl (FeO2+)-EDTA complex.
منابع مشابه
Ligand-enhanced reactive oxidant generation by nanoparticulate zero-valent iron and oxygen.
The reaction of zero-valent iron or ferrous iron with oxygen produces reactive oxidants capable of oxidizing organic compounds. However, the oxidant yield in the absence of ligands is too low for practical applications. The addition of oxalate, nitrilotriacetic acid (NTA), or ethylenediaminetetraacetic acid (EDTA) to oxygen-containing solutions of nanoparticulate zero-valent iron (nZVI) signifi...
متن کاملOxidizing intermediates generated in the Fenton reagent: kinetic arguments against the intermediacy of the hydroxyl radical.
It has long been recognized that the aqueous mixture of hydrogen peroxide and ferrous ion, known as the Fenton reagent, generates powerful oxidants. Furthermore, the chemical intermediates and reaction pathways of the type generated by this reagent have been implicated in oxidative damage in biological systems. Although the subject continues to be debated, the hydroxyl radical (.OH) is generall...
متن کاملPyrite-induced hydroxyl radical formation and its effect on nucleic acids
BACKGROUND Pyrite, the most abundant metal sulphide on Earth, is known to spontaneously form hydrogen peroxide when exposed to water. In this study the hypothesis that pyrite-induced hydrogen peroxide is transformed to hydroxyl radicals is tested. RESULTS Using a combination of electron spin resonance (ESR) spin-trapping techniques and scavenging reactions involving nucleic acids, the formati...
متن کاملThe reaction of ferrous horseradish peroxidase with hydrogen peroxide.
Hydrogen peroxide reacts with ferrous horseradish peroxidase and converts it to oxyperoxidase in a sequence of two reactions. The first is the reaction of ferrous peroxidase with HzOz to form Compound II; the second is the reaction of Compound II with HzOz to form oxyperoxidase. Both reactions follow second order kinetics, being first order with respect to each of the reactants. They proceed wi...
متن کاملComplex-formation between cytochrome c and cytochrome c peroxidase. Equilibrium and titration studies.
1. Physical studies of complex-formation between cytochrome c and yeast peroxidase are consistent with kinetic predictions that these complexes participate in the catalytic activity of yeast peroxidase towards ferrocytochrome c. Enzyme-ferricytochrome c complexes have been detected both by the analytical ultracentrifuge and by column chromatography, whereas an enzyme-ferrocytochrome c complex w...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of biological chemistry
دوره 261 15 شماره
صفحات -
تاریخ انتشار 1986