Glutathione peroxidase 5 (GPX5)

Glutathione peroxidase 5 (GPX5) is a selenium-independent antioxidant enzyme that is a member of the glutathione peroxidase family, but uniquely contains cysteine instead of selenocysteine at its active site[1][3]. It is predominantly and specifically expressed in the epithelial cells of the caput region of the mammalian epididymis, where it is synthesized, secreted, and binds to maturing spermatozoa[1][3][4]. GPX5 protects sperm from oxidative stress, specifically neutralizing reactive oxygen species (ROS) such as hydrogen peroxide (H₂O₂) and organic hydroperoxides, thereby safeguarding the structural and genetic integrity of sperm during epididymal transit[1][3]. Knockout or deficiency of GPX5 leads to sperm DNA damage and increased rates of miscarriage and embryonic defects in progeny, highlighting its crucial role in male fertility by preserving sperm chromatin and preventing oxidative injury[1][2][3]. GPX5 does not appear to be directly targeted by any approved drugs and is primarily of biological rather than pharmacological interest as a reproductive antioxidant[1][3].

Other names

Epididymal secretory glutathione peroxidaseEGLPGPx-5GSHPx-5Epididymis-specific glutathione peroxidase-like proteinGlutathione peroxidase 5, epididymal androgen-related proteinHEL-S-75pepididymal secretory glutathione peroxidaseepididymis secretory sperm binding protein Li 75p