Presence of a high-molecular-weight form of catalase in enzyme purified from mouse liver

Ultracentrifugation studies of purified mouse hepatic catalase revealed that 5-7% of the total material consists of a form with a higher molecular weight than the bulk of the catalase. The two components were separated by sucrose-gradient centrifugation. Polyacrylamide-gel electrophoresis (in borate buffer) demonstrated that high-molecular-weight catalase is enriched in a more slowly migrating component, and sodium dodecyl sulphate/polyacrylamide gel-electrophoresis demonstrated that the molecular weight of the subunits of the high-molecular-weight material is identical with that of the subunits of the major form. These results suggest that high-molecular-weight catalase consists of subunits that are not markedly distinct from those present in the normal catalase tetramer.