关键词:  , 茶花粉, 超氧化物歧化酶, 性质

Abstract: Superoxide dismutase from camellia pollen was purified to homogeneity and assayed to be Cu, Zn-SOD accordingto its specific sensitivities to hydrogen peroxide, cyanogens potassium and chloroform-alcohol. The molecular weights of the SOD and its subunit were 69.5kD and 34.7kD, respectively. Isoelectric point analysis indicated that it was an acidic protein whose isoelectric point was pH4.1. The N-terminal amino acid of the enzyme was identified to be Gly by DNS- Cl method. Its content of α-Helix was also assayed to be approximately 21.8% according to the result of circular dichroism (CD) spectra. The effects of pH, temperature, chemical reagents and metal ions on SOD were studied respectively in its molecular stability experiments. Results showed that the optimum temperature and pH of the enzyme were 25℃ and 6.5 respectively. It lost its activity entirely when the pH was higher than 10, and its activity was also highly inhibited when KCN, H2O2, SDS and β- mercaptoethanol existed, but 4mol/L carbamide had no effect on it. The activity of the SOD whose metal ions were driven out by EDTA recovered totally after combining with Cu2+, Zn2+ but only partly recovered after combing with Mn2+, Mg2+.

Key words: camellia pollen, superoxide dismutase, characterization