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PubMed · 10694060

Activated oxygen generation from thylakoids: a novel spin trap.

C L Sgherri·C Pinzino·E Samaritani·F Navari-Izzo
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Abstract

Using a novel phosphorylated spin trap, 5-(diethoxyphosphoryl)-5-methyl-1-pyrroline-N-oxide (DEPMPO), an analogue of the commonly used spin trap 5,5'-dimethyl-1-pyrroline N-oxide (DMPO), we have investigated the production of oxygen radical species under illumination of thylakoids from wheat (Triticum durum Desf cv. Ofanto). DEPMPO reacted with superoxide (O2*-) and hydroxyl radical (HO*) forming distinctive spin trap adducts. Spectra of (O2*-) and HO* adducts of DEPMPO were recorded in the presence of xanthine/xanthine oxidase and FeSO4/H2O2, respectively, and computer simulation of spectra was performed. During illumination of thylakoids both O2*- and HO* were detected as well. Transition metals catalysed transformation of O2*- into HO*. The conversion was enhanced by H2O2 and prevented by exogenous superoxide dismutase and catalase. The presence of a thylakoid-bound superoxide dismutase, whose activity was inhibited by H2O2 and diethyldithiocarbamic acid, was responsible for H2O2 production from O2*- and thus for HO* generation.

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Cyclic N-OxidesElectron Spin Resonance SpectroscopyHydroxyl RadicalLightReactive Oxygen SpeciesSpin LabelsSuperoxide DismutaseSuperoxidesThylakoidsTriticumJournal ArticleResearch Support, Non-U.S. Gov't

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C L Sgherri, C Pinzino, E Samaritani, F Navari-Izzo. 1999. Activated oxygen generation from thylakoids: a novel spin trap.. https://doi.org/10.1080/10715769900301511

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