Abstract
A minor component in rat liver microsomes which reacted with anti-catalase antibodies was investigated. The molecule possessed no enzyme activity and was rapidly labelled by an injected radioactive amino acid. Effective separation of this entity from mature catalase tetramer was substantially achieved by treatment with microsome extracts (pH 6.0) (with sodium deoxycholate) and by desalination with ammonium sulfate at 30 % (w/v) . The possi-bility of this minor component being a monomeric catalase subunit existing as a precursor to the mature enzyme has been suggested.
