GPX5 orthologs of the mouse epididymis-restricted and sperm-bound selenium-independent glutathione peroxidase are not expressed with the same quantitative and spatial characteristics in large domestic animals

Seminal Plasma Proteins as Potential Markers of Relative Fertility in Boars

“…Although we have previously speculated that this protein may be lipocalin-type prostaglandin D synthase (Foxcroft et al, 2008), this study confirmed its identity using MS as glutathione peroxidase-5. Glutathione peroxidase-5 is a seleniumindependent free radical scavenger that is restricted to the male reproductive tract (Grignard et al, 2005). It has been shown to bind to the head of the spermatozoa in mice (Vernet et al, 1997) and is thought to protect the sperm plasma membrane from attacks by free radicals (Grignard et al, 2005).…”

“…Glutathione peroxidase-5 is a seleniumindependent free radical scavenger that is restricted to the male reproductive tract (Grignard et al, 2005). It has been shown to bind to the head of the spermatozoa in mice (Vernet et al, 1997) and is thought to protect the sperm plasma membrane from attacks by free radicals (Grignard et al, 2005). Other studies have detected another glutathione peroxidase, phospholipid hydroperoxidase (GPX4) in the seminal plasma of boars and are investigating its role in sperm quality (Dube et al, 2004;Bailey et al, 2005).…”

Crystal Structures of a Poplar Thioredoxin Peroxidase that Exhibits the Structure of Glutathione Peroxidases: Insights into Redox-driven Conformational Changes

“…Depending on the active site amino acid, these enzymes are generally classified into two groups: one contains SeCys at its active center (at least four out of five isozymes belong to selenium-containing GPX in mammals), the other contains a regular cysteine (the mammalian epididymis-specific isoform, GPX-5). 26 The non-selenium type GPX-5 is speculated to serve as the backup enzyme for the selenium-containing GPX to counteract ROS-mediated damage of sperm cells, since selenium deficiency causes male infertility and selenium-containing GPX is suspected to be a candidate for the defective molecule. 26,27 The activity of selenium-independent GPX is low and, hence, its contribution as a GSH-dependent peroxide scavenger is ambiguous.…”

“…26 The non-selenium type GPX-5 is speculated to serve as the backup enzyme for the selenium-containing GPX to counteract ROS-mediated damage of sperm cells, since selenium deficiency causes male infertility and selenium-containing GPX is suspected to be a candidate for the defective molecule. 26,27 The activity of selenium-independent GPX is low and, hence, its contribution as a GSH-dependent peroxide scavenger is ambiguous. 27 Nevertheless, the overall structures of all mammal GPX monomers are similar, except that the environment around their active site catalytic residues is quite different.…”

Activity of antioxidant enzymes and their mRNA expression in different reproductive tract tissues of the male roe deer (Capreolus capreolus) during the pre-rut and rut seasons

“…Protection of these processes in the testis and epididymis against the harmful effects of reactive oxygen species (ROS) is provided mainly by antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), which have complementary roles in cellular tissues and sperm cells (Drevet, 2006;Gancarczyk et al, 2006;Marti et al, 2007;Kowalowka et al, 2008;Koziorowska-Gilun et al, 2011). Several isoforms of GPx have been detected, however, phospholipid hydroperoxide glutathione peroxidase (PHGPx, GPx4) and an epididymal-specific GPx (GPx5) have been shown to play a significant role in the antioxidant enzyme defence system of the male reproductive tract of various animal species (Beiglböck et al, 1998;Vernet et al, 2004;Grignard et al, 2005;Drevet, 2006;Boitani and Puglisi, 2008;Chabory et al, 2010;Koziorowska-Gilun et al, 2013).…”