Partial biochemical characterization of Cu,Zn-superoxide dismutase extracted from eggs of hens (Gallus gallus domesticus)

•The presence of superoxide dismutase in egg yolk from hens was confirmed.•The dynamics of changes in activity of superoxide dismutase during storage was defined.•Biochemical characteristics of superoxide dismutase from egg yolk of hens was described.

Biochemical characteristics of Cu,Zn-SOD derived from hen egg white and egg yolk were determined, and compared with those of enzymes from erythrocytes of hens and SOD standard. The presence of dimer with a molecular weight of 33.38 ± 0.34 kDa, and pI of 6.30 ± 0.15 was confirmed in samples of SOD extracted from egg yolk. Cu,Zn-SOD isolated from egg yolk had an optimum at pH 6. Average SOD activity in egg yolk was 98.5 ± 19.5 U·g−1 while in egg white reached 6.1 ± 0.8 U·g−1. Changes in SOD activity of the egg yolk during its storage for 200 days were also described. FTIR analysis confirmed that the enzymatic protein described in this study was SOD, while MALDI-TOF analysis confirmed only SOD from erythrocytes. Since eggs are a cheap and easily obtainable source of SOD, this enzymatic protein could be used in food, cosmetic or pharmaceutical industries.