Crystallographic data of the selenoenzyme glutathione peroxidase

Glutathione peroxidase prepared from bovine erythrocytes yields small, but well-ordered plate-like crystals. X-ray investigation shows them to belong to monoclinic space group C2. Unit cell dimensions are: $\text{a = 90.4}\text{A}\text{?}\text{, b = 109.5}\text{A}\text{?}\text{, c = 58.6}\text{A}\text{?}$, β = 99 ° ± 15 min. The crystal density is ?_c = 1.36 ± 0.02 g.cm^?3. Consequently, the asymmetric unit of the crystal cell is occupied by one tetrameric molecule of M_r 84,000. Matthew's (1968) parameter Γ_M is calculated to be 1.71 ų/dalton.