Studies of peroxisomes. VIII. Evidence for framework protein of the cores of rat liver peroxisomes.

The cores of peroxisomes were purified 670 fold from a rat liver homogenate and the protein in the preparation was examined by sodium dodecyl sulfate(SDS)-polyacrylamide gel electrophoresis. Two bands of protein were detected on 10% polyacrylamide gel, and their molecular weights were calculated to be about 32,000 and 27,000. On treatment of the core fraction with alkali, urate oxidase was solubilized and on 10% polyacrylamide gel this fraction gave a single band of protein with an estimated molecular weight of 32,000. These results suggests that the protein component having a molecular weight of 27,000 is the framework protein of the core of rat liver peroxisomes.