Enzyme that protects the brain from free radical injury is:

- Superoxidase dismutases (SODs) are found in many cell types and conve O2 radicals into hydrogen peroxide This group of enzymes includes:- Manganese-SOD localized in mitochondria Copper-zinc- SOD found in the cytosol. - One of the earliest discovered hereditary forms of Amyotrophic lateral sclerosis (ALS) has mutations in the gene encoding copper-zinc superoxide dismutase (SOD1) on chromosome 21; this variant accounts for about 20% of familial cases.