Studies on Peroxisomes. VII. Effect of the Light Component on the Formation of the Core-DAAO Complex of Rat Liver Peroxisomes

Abstract

Partially purified peroxisomal core containing and not containing the light component was isolated from the liver homogenate of the rat and used for formation of the core complex bearing D-amino acid oxidase (DAAO). When either core preparation was vigorously stirred in the DAAO preparation at 0°C for 30 min and then centrifuged at 20, 000g for 30 min, the urate oxidase activity as a core marker was found in the pellet in which a small amount of DAAO activity was also found. The peroxisomal core containing the light component had a tendency to constitute the core-DAAO complex more easily than core without the component. The light component was extracted from the partially purified core (100-fold over the liver homogenate). The light component had a high cholesterol content. An experiment on reconstitution of the approximate native core complex using preparations of the light component, DAAO and the highly purified core (about 450-fold over the liver homogenate) showed that the peroxisomal core complex seemed to consist of urate oxidase, other peroxisomal oxidases, such as DAAO, and the light component, and also showed that DAAO and the light component probably underwent some interactions when binding to the core.