Experimental evidence suggesting that H2O2 is produced within the thylakoid membrane in a reaction between plastoquinol and singlet oxygen

Article ID	Journal	Published Year	Pages	File Type
10870465	FEBS Letters	2015	8 Pages	PDF

Abstract

Plastoquinol (PQH2-9) and plastoquinone (PQ-9) mediate photosynthetic electron transfer. We isolated PQH2-9 from thylakoid membranes, purified it with HPLC, subjected the purified PQH2-9 to singlet oxygen (1O2) and analyzed the products. The main reaction of 1O2 with PQH2-9 in methanol was found to result in formation of PQ-9 and H2O2, and the amount of H2O2 produced was essentially the same as the amount of oxidized PQH2-9. Formation of H2O2 in the reaction between 1O2 and PQH2-9 may be an important source of H2O2 within the lipophilic thylakoid membrane.

Keywords

DNP-INT Photosystems I and II, respectively HEPES HO2 P680 Pheo 1O2 Chl 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid O2−PSI and PSII ROS Hydrogen peroxide Singlet oxygen Superoxide anion radical hydroperoxyl radical Chlorophyll Thylakoid membrane Photosystem II Methanol MeOH plastoquinone Reactive oxygen species