Letter: Preliminary crystallographic data for spinach superoxide dismutase

Superoxide dismutase from spinach leaves was salted out with ammonium sulphate. The resulting crystals were monoclinic, space group C2, with unit cell dimensions $\text{a = 166.2}\text{A}\text{?}\text{, b = 46.1}\text{A}\text{?}\text{, c = 85.6}\text{A}\text{?}\text{and}\text{β = 99.3 °}$. Considerations of cell volume and protein molecular weight indicated two molecules of superoxide dismutase in the asymmetric unit.