Ceruloplasmin, the major copper-carrying protein in blood, also functions as an important extracellular antioxidant. What is the biochemical mechanism of its antioxidant action?

• A Direct scavenging of superoxide radicals
• B Hydrolysis of lipid peroxides
• C Reduction of glutathione disulfide
• D Oxidation of ferrous iron to ferric iron ✓

Explanation

Ceruloplasmin exhibits ferroxidase activity, converting highly reactive ferrous iron (Fe2+) to ferric iron (Fe3+). This prevents Fe2+ from participating in the Fenton reaction, thereby inhibiting hydroxyl radical generation. It does not directly scavenge superoxide or reduce glutathione.

Reference: Harper's Illustrated Biochemistry, 31st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.