Extracellular superoxide dismutase [Cu-Zn]

Extracellular superoxide dismutase [Cu-Zn] (SOD3; EC-SOD) is a 240-amino-acid protein that catalyzes the conversion of superoxide radicals to hydrogen peroxide and oxygen in the extracellular space, thereby protecting tissues from oxidative damage (UniProt: P08294). The protein functions as an antioxidant enzyme in extracellular compartments throughout the body.

SOD3 is expressed in various tissues including lung, heart, and vasculature, where it provides defense against reactive oxygen intermediates. No specific disease associations are documented in UniProt for this protein.

SOD3 shows elevated abundance in Alzheimer's Disease brain tissue. Quantitative proteomics analysis of post-mortem AD brain compared to age-matched controls detected SOD3 across multiple subcellular fractions, with an upward direction and mean log2 fold-change of 1.22 (Chaparral AD proteomics). This increase may reflect compensatory antioxidant responses to oxidative stress associated with neurodegeneration in AD.