The availability of a spectrophotometric assay for superoxide dismutase (SOD) activity and of an activity stain applicable to polyacrylamide gels facilitated the isolation of SODS from a variety of sources. A manganese-containing SOD (Mn-SOD) was rather quickly isolated from Escherichia coli (13) and from chicken liver mitochondria and an iron-containing SOD (Fe-SOD) was isolated from E. coli. These SODS are widely distributed, abundant and stable, and thus are well-suited for the studies of structure, function, and evolution. In some cases, the distribution of SODS provides a clear indication of evolutionary history, while in other cases remain enigmatic. Mitochondria contain a Mn-SOD, while the cytosols of eukaryotic cells contain a Cu,Zn-SOD. The mitochondria1 Mn-SOD is strikingly homologous to the Mn-SODs/Fe-SODs found in prokaryotes, but bears no resemblance to the cytosolic Cu,Zn-SOD, which supports the idea of an endosymbiotic origin for this organelle.
|Number of pages
|Progress in nucleic acid research and molecular biology
|Published - Jan 1 1991
ASJC Scopus subject areas
- Molecular Biology