Ceruloplasmin antioxidant activity

In addition, ceruloplasmin shows oxidase activity towards bifunctional aromatic amines and phenols, but with much higher Km values, and also to a group of pseudosubstrates that can rapidly oxidize Fe11. Ceruloplasmin may also have a role as a serum antioxidant. 

There is evidence of an increase in the redox-active fraction of plasma Cu in human aging [54]. This arises because of the apparent increase in the proportion of an oxidized form of ceruloplasmin, an antioxidant ferroxidase that carries > 90% of total plasma Cu. The damaged ceruloplasmin allows the Cu it binds (6 moles per protein unit) to become EPR-detectable [54]. This is an example of how damage to a cuproprotein may unleash abnormal redox chemistry, a principle that we believe underhes the pathology of AD. 

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