Nitration of manganese superoxide dismutase in cerebrospinal fluids is a marker for peroxynitrite-mediated oxidative stress in neurodegenerative diseases

Peroxynitrite can nitrate tyrosine residues of proteins. We examined nitrot yrosine-containing proteins in cerebrospinal fluid of 66 patients with neur ogenic disease by immunoblot analysis. Nitrated tyrosine residue-containing protein was observed in the cerebrospinal fluid and was concluded to be ma nganese superoxide dismutase (Mn-SOD). The nitrated Mn-SOD level was striki ngly elevated in amyotrophic lateral sclerosis patients and was slightly in creased in Alzheimer's and Parkinson's disease patients, whereas an elevate d Mn-SOD level was observed only in progressive supranuclear palsy group.