USE OF LIVER HOMOGENATES FOR STUDIES ON THE INTRACELLULAR SITE OF UBIQUINONE BIOSYNTHESIS

Abstract

Mevalonic acid was incorporated into the ubiquinone and sterol fractions of rat-liver homogenates. The incorporation of mevalonate was increased approximately 10-fold in the total non-saponifiable matter including sterol by use of the in vitro homogenate system as compared with intact rats. The incorporation into the ubiquinones was decreased. The addition of potential ring precursors, p-hydroxybenzoic acid, L-phenylalanine, or L-tyrosine to the homogenate system did not increase incorporation of mevalonate into ubiquinone.Incubation of subcellular fractions from rat-liver homogenates demonstrated that supernate plus either mitochondria or microsomes were necessary for the biosynthesis of ubiquinone.