[Enzymologic study of the structural organization of the matrix or rat liver peroxisomes]

The effect of ionic strength and pH on the release of some enzymes of the matrix of peroxisomes in rat's liver was studied. Catalase, L ALpha-hydroxy acid oxidase, isocitrate dehydrogenase, glycerophosphate dehydrogenase and lactate dehydrogenase were easily released from the particles during their lysis and treatment with 0.16 M KCl, whereas urate oxidase, NADH cytochrome c reductase and D-amino acid oxidase were not solubilized. After the solubilization of peroxisomal membrane by 0.2% Triton X-100, the remaining core contained about 50% amino acid oxidase activity, and had 1.28--1.30 g/cm3 density. These results suggest that D-amino acid oxidase associates with urate oxidase in the peroxisomal core.