The peroxidatic and catalatic activity of catalase in normal and acatalasemic mouse liver.

Monomeric, dimeric and tetrameric forms of mouse liver catalase have been shown to express peroxidatic activity while the tetrameric form expresses the catalatic activity. Autosomally inherited acatalasemia, produced by X-ray irradiation of mice results in almost complete loss of catalatic activity of catalase but has o effect on the peroxidatic activity. Liver catalase from normal and acatalasemic mice was purified by following the catalatic and peroxidatic activity, respectively. Antiserum produced in rabbit against catalase from normal mouse completely precipitated the catalatic and peroxidatic activity from normal liver, and peroxidatic activity from the acatalasemic liver homogenate. Similar results were obtained when antiserum against peroxidase from acatalasemic mice was used. These studies indicate that acatalasemia in mice is due to a structural gene mutation which leads to synthesis of structurally altered catalase subunits. The altered subunits express peroxidatic activity but do not combine to form a tetramer which expresses catalatic activity.