Superoxide Dismutase from Ryegrass Leaves ( Lolium perenneperennial )

Superoxide dismutase(SOD) separated and extracted from ryegrass leaves( Lolium perenneperennial ) was purified by fraction precipitation by ammonium sulfate and column chromatography. The purified enzyme is found to be a copper/zinc superoxide dismutase as assayed by its sensitivity to KCN and H 2 O 2 . Electrophoretic analysis indicated that the enzyme contains two homogenous subunits with molecular weight of 15 900 with N terminal being alanine and maximum ultraviolet absorption at 254 nm. The SOD from ryegrass leaves is thermal stable with activity loss of 27% at 65 ℃ for an hour. Quantitative analysis of amino acids revealed that this protein was composed of 212 amino acids and lack of tryptophan.