Anti-glutathione peroxidase 1 (GPx-1, 175-194)

Glutathione peroxidase 1 has a role in detoxification of hydrogen peroxide and is one of the most important antioxidant enzymes in humans. It exists as a homotetramer which localises to the cytoplasm. It belongs to the glutathione peroxidase family. Glutathione peroxidase 1 is one of few proteins in higher vertebrates to contain selenocysteine, which occurs at the active site of glutathione peroxidase and is coded by UGA, that normally functions as a translation termination codon. This protein has a polyalanine sequence polymorphism in the N-terminal region, which includes three alleles with five, six or seven alanine repeats. The allele with five alanine repeats is significantly associated with breast cancer risk. Two alternatively spliced isoforms have been identified.