FORMATION AND CONVERSION OF MACROMOLECULAR PRECURSOR(S) IN THE BIOSYNTHESIS OF CARBAMYL PHOSPHATE SYNTHETASE

Abstract
The synthesis de novo of carbamyl phosphate synthetase in slices of liver from thyroxine-treated tadpoles involves initally the synthesis of macro-molecular precursor(s) which are converted to active enzyme in a mitochondrial fraction. Puromycin and respiratory inhibitors have no significant effect on the conversion process. A biphasic temperature effect and a high temperature quotient suggest the involvement of con-formational changes during the process. Attempts to obtain a cell-free system capable of converting precursor(s) to active enzyme have been unsuccessful to date.