Species specific features of the distribution and multiplicity of mammalian liver catalase

Abstract

The multiplicity and subcellular distribution of liver catalase activity have been studied in 10 species of mammals, in order to clarify comparative aspects of the properties of this enzyme. All mammals studied, except mouse, displayed the bulk of liver catalase activity in the cytosol, but the relative proportions of soluble and particulate activity varied quite markedly between species. Sheep, pig, and guinea pig provided the richest sources of supernatant liver catalase; while mouse, rat and pig contained the highest peroxisomal catalase activity. Rabbit, mouse, and rat liver supernatants exhibited 3–4 multiple forms of catalase activity, and displayed an electrophoretic pattern which was distinctly different to that of the aqueous peroxisomal extract. This latter fraction contained a single form of activity of higher anodal migration; a pattern of which was similar to that observed in all fractions of the other species examined. These results may be reconciled with current knowlledge of catalase genetics, subunit structure, and turnover by means of a postulated epigenetic mechanism, involving modifications of the enzyme in rabbit, rat, and mouse liver cytosol.