Distribution of glutathione peroxidases glutathione reductase in rat brain mitochondria

Abstract

The distribution of glutathione reductase (GR), gtutathione peroxidase (GPx) and phosphotipid hydroperoxide giutathione peroxidase (PHGPx) in isolated rat brain mitochondria was investigated, using a fractionation procedure for the separation of inner and outer membranes, contact sites between the two membranes and a soluble Fraction mainly originating from the mitochondrial matrix. The data indicate that GW and GPx are concentrated in the soluble fraction, with a minor portion of the two enzymes being associated with the contact sites. PHGPx is localized largely in the inner membrane. The possible functional significance of these findings is discussed.

Reversible oxidation and inactivation of the tumor suppressor PTEN in cells stimulated with peptide growth factors

“…Catalase is localized exclusively in peroxisomes, so that elimination of cytosolic H 2 O 2 by catalase requires its diffusion into these organelles. The major isoform of GPx, GPx1, is largely restricted to the cytosol but is also present in mitochondria (26). The Prx family of peroxidases includes at least six isoforms in mammalian cells (27).…”

Molecular biology of glutathione peroxidase 4: from genomic structure to developmental expression and neural function

“…tissues (Bourre et al, 2000). In brain mitochondria, GPx4 activity was mainly recovered in the inner mitochondrial membrane fraction (Panfili et al, 1991). Direct evidence of GPx4 distribution came from comparative expression analysis, revealing onset of expression as early as during gastrulation (Yant et al, 2003;Borchert et al, 2006).…”

Mitochondrial Production of Hydrogen Peroxide Regulation by Nitric Oxide and the Role of Ubisemiquinone

“…First, based on fractionation experiments, the classic glutathione peroxidase has been found to reside only in the mitochondrial matrix (40), whereas phospholipid hydroperoxid e glutathione peroxidase is believed to be localized in the inner membrane and contact junctions between the inner and outer membrane (41,42). Overall, the intermembrane space appears to possess a more decient peroxidase activity than the mitochondrial matrix.…”