SELENIUM: ANTI OXIDANT, ANTI CARCINOGEN AND IMMUNE SYSTEM BOOSTER Unglycosylated recombinant human glutathione peroxidase 3 mutant from Escherichia coli is active as a monomer Scientific Reports Selenocysteine muscle pain ** **A lack of selenium cause muscle pain mechanism of action.** Selenium exerts its biological functions via molecules called selenoproteins which contain the amino acid cysteine with Modeling the Catalytic Cycle of Glutathione Peroxidase by Nuclear Magnetic Resonance Spectroscopic Analysis of Selenocysteine Selenenic Acids Journal of the American Chemical Society