Journal article
S-glutathionyl-(chloro)hydroquinone reductases: a new class of glutathione transferases functioning as oxidoreductases
Drug metabolism reviews, Vol.43(2), pp.307-316
05/2011
Handle:
https://hdl.handle.net/2376/110378
PMCID: PMC3233476
PMID: 21425927
Abstract
Glutathione transferases (GSTs) are best known for transferring glutathione (GSH) to hydrophobic organic compounds, making the conjugates more soluble. However, the omega-class GSTs of animals and the lambda-class GSTs and dehydroascorbate reductases (DHARs) of plants have little or no activity for GSH transfer. Instead, they catalyze GSH-dependent oxidoreductions. The lambda-class GSTs reduce disulfide bonds, the DHARs reduce the disulfide bonds and dehydroascorbate, and the omega-class GSTs can reduce more substrates, including disulfide bonds, dehydroascorbate, and dimethylarsinate. Glutathionyl-(chloro)hydroquinone reductases (GS-HQRs) are the newest class of GSTs that mainly catalyze oxidoreductions. Besides the activities of the other three classes, GS-HQRs also reduce GS-hydroquinones, including GS-trichloro-p-hydroquinone, GS-dichloro-p-hydroquinone, GS-2-hydroxy-p-hydroquinone, and GS-p-hydroquinone. They are conserved and widely distributed in bacteria, fungi, protozoa, and plants, but not in animals. The four classes are phylogenetically more related to each other than to other GSTs, and they share a Cys-Pro motif at the GSH-binding site. Hydroquinones are metabolic intermediates of certain aromatic compounds. They can be auto-oxidized by O(2) to benzoquinones, which spontaneously react with GSH to form GS-hydroquinones via Michael's addition. GS-HQRs are expected to channel GS-hydroquinones, formed spontaneously or enzymatically, back to hydroquinones. When the released hydroquinones are intermediates of metabolic pathways, GS-HQRs play a maintenance role for the pathways. Further, the common presence of GS-HQRs in plants, green algae, cyanobacteria, and halobacteria suggest a beneficial role in the light-using organisms.
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Details
- Title
- S-glutathionyl-(chloro)hydroquinone reductases: a new class of glutathione transferases functioning as oxidoreductases
- Creators
- Sara M Belchik - School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-7520, USALuying Xun
- Publication Details
- Drug metabolism reviews, Vol.43(2), pp.307-316
- Academic Unit
- Molecular Biosciences, School of
- Publisher
- England
- Grant note
- T32 GM008336-15 / NIGMS NIH HHS T32 GM008336-16 / NIGMS NIH HHS T32 GM008336 / NIGMS NIH HHS
- Identifiers
- 99900547123501842
- Language
- English
- Resource Type
- Journal article