Liver enzyme induction by 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (DDT) is accompanied by an increase in the specific activity of elongation factor 1

Abstract

Homogenates of liver were obtained from control rats and from rats that had received DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane]. The postmicrosomal supernatant fractions were used for the purification of elongation factor 1 by hydroxyapatite chromatography and phosphocellulose chromarography. The amount of binding factor present was essentially the same for both groups of animals, but the specific activity, as measured by the binding assay, was about twice as high in the DDT-treated preparations. After sucrose-gradient sedimentation, the difference in specific activity was found to reside in the low-molecular-weight (50000) form of elongation factor 1. The implications of an increased reactivity of elongation factor 1 during the induction of membrane enzymes are discussed.