Superoxide dismutase (SOD) is a critical antioxidant enzyme present in nearly all living cells exposed to oxygen. It catalyzes the rapid conversion of superoxide radicals-harmful byproducts of cellular metabolism-into hydrogen peroxide and molecular oxygen, thereby protecting cells from oxidative damage. SOD achieves this through highly efficient redox cycling at its active site, which contains essential metal cofactors such as copper, zinc, manganese, or iron, depending on the SOD isoform. These metal ions facilitate electron transfer, enabling SOD to neutralize superoxide radicals at rates limited only by molecular diffusion.

Functionally, SOD plays a vital role in cellular defense against oxidative stress, maintaining metabolic and mitochondrial integrity. Mutations in the SOD1 gene are linked to familial amyotrophic lateral sclerosis (ALS), while altered SOD activity is implicated in diseases such as Parkinson’s, Alzheimer’s, Down syndrome, cardiovascular disease, and various inflammatory and neurodegenerative disorders.