PARTIAL PURIFICATION OF GLUTATHIONE PEROXIDASE ENZYME FROM WOMEN WITH BREAST CANCER.

Area of Science:

• Biochemistry
• Enzymology
• Oncology

Background:

• Glutathione peroxidase (GPX) is a crucial antioxidant enzyme.
• Altered GPX activity is implicated in various diseases, including cancer.
• Investigating GPX in breast cancer serum provides insights into disease mechanisms.

Purpose of the Study:

• To purify and characterize glutathione peroxidase (GPX) enzyme from the serum of women with breast cancer.
• To determine the activity levels of GPX in breast cancer patients compared to healthy individuals.
• To establish the optimal conditions for the activity of partially purified GPX.

Main Methods:

• Serum samples were collected from 60 women with breast cancer and 30 healthy individuals.
• GPX was purified using ammonium sulfate precipitation, dialysis, ion exchange chromatography (DEAE-Cellulose), and gel filtration chromatography (Sephadex G-100).
• Enzyme activity was assayed under varying substrate concentrations, pH, temperature, and time; kinetic parameters (Vmax, Km) were determined using Lineweaver-Burk plot.

Main Results:

• A significant decrease in GPX activity was observed in the serum of women with breast cancer (p<0.0001).
• A main protein band corresponding to GPX was isolated.
• Optimal conditions for partially purified GPX activity were determined: 0.1 mM H2O2 substrate concentration, pH 8.5, 37°C, and 5 minutes incubation time.
• Kinetic parameters: Vmax = 3.125 IU/L, Km = 0.0179 M.

Conclusions:

• GPX activity is significantly reduced in breast cancer patients' serum.
• The study successfully purified and characterized GPX from breast cancer serum.
• Understanding GPX's altered activity and optimal conditions may contribute to breast cancer research and diagnostics.