Thermodynamic Characterization of Kidney Superoxide Dismutase from Labeo rohita Exposed to the Mixture of Lead and Chromium
Thermodynamic Characterization of Kidney Superoxide Dismutase from Labeo rohita Exposed to the Mixture of Lead and Chromium
Huma Naz1,*, Sajid Abdullah2, Khalid Abbas2 and Muhammad Anjum Zia3
ABSTRACT
Toxic effect of lead (Pb)+chromium (Cr) mixture on superoxide dismutase (SOD) from kidney of Labeo rohita exposed to sub-lethal concentration for 14 days was evaluated. After purification, specific activity of enzyme was 1750.13 and 1272.72 U mg-1 in kidney of metal exposed and control fish, respectively. The enzyme from metal exposed kidney was 2.68 fold purified with 58.73 % age recovery. Results of characterization showed that SOD had broad range of pH from 4 to 8.5 but show maximum activity at pH 7 and 7.5 for stressed and control fish, respectively. At 30°C activity of SOD was maximum for both control and stressed fish. At 40 °C the enthalpy of denaturation (∆H*)for metal treated and control fish were 0.373 and 0.736 KJ mol-1, respectively and decreases with further increase in temperature (70 °C) until it was 0.132 and 0.495 KJ mol-1, respectively. The free energy (ΔG*) of thermal denaturation for metal treated and control fish were 58.45 and 58.79 KJ mol-1, respectively at 40 °C and increases with increase in temperature until it remained 62.65 and 63.18 KJ mol-1, respectively at 70 °C. The negative value of entropy of inactivation (ΔS*) shows that the superoxide dismutase is stable thermodynamically.
To share on other social networks, click on any share button. What are these?
