Anticancer agent 3-bromopyruvic acid forms a conjugate with glutathione
Izabela Sadowska-Bartosz1, Rafal Szewczyk2, Lukasz Jaremko3
1Department of Biochemistry and Cell Biology, Faculty of Biology and Agriculture, University of Rzeszów, Rzeszów, Poland.
Background:
3-Bromopyruvic acid (3-BP), a glycolytic inhibitor and a promising anticancer compound, induces oxidative stress and depletes cells of glutathione (GSH). The causes of GSH loss remain unclear. The aim of this study was to ascertain whether 3-BP forms a conjugate with glutathione.
Methods:
GSH was incubated with various amounts of 3-BP and the extent of reaction was titrated with (1)H NMR and (1)H-(1)H NMR. The reaction outcome was identified by MS/MS. Intracellular formation of the conjugate was assessed in cells treated with 3-BP and 3-BP((13)C) and analyzed using the targeted LC-MS/MS method in negative ionization MRM mode.
Results:
3-BP was found to react with GSH in a 1:1 ratio forming an S-conjugate. The same conjugate was formed intracellularly in erythrocytes and MCF-7 cells.
Conclusions:
3-BP reacts with GSH in the absence of cells and intracellularly. This reaction appears to be the main cause of GSH loss in 3-BP treated cells.
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