Author/Authors :
Haddad, Namir I. A. University of Baghdad - College of Science - Department of Chemistry, Iraq , Yuan, Qinsheng University of Science and Technology - College of Bio-engineering - Laboratory of Bioreactor Engineering, China
Abstract :
The Cu,ZnSOD was purified from Radix lethospermi seed by ammonium sulphate precipitation followed by column chromatography using DEAE-FF, Sephadex G- 100 and hydroxylapatite chromatography. Before extraction lipid was removed by super critical fluid extraction (SCF). Pure copper,zinc superoxide dismutase had a specific activity of 3555.9 units per milligram protein and was purified 211.5-fold., with a yield of 19.3 %. The isozyme has a molecular weight of 33 KDa and is composed of two non-covalently joined equal subunits, having 0.93±0.02 g.atom Cu and 0.79±0.01 g.atom Zn for each. The purified enzyme was stable over a pH rarige of 6.0-9.0 at 25°C and a temperature range of 25-45 °C. The purified RLS Cu,ZnSOD was sensitive to both cyanide and hydrogen peroxide which is typical of Cu,Zn SODs but was not inhibited by DTT, NaN3, and β-mercaptoethanol.
