Polymorphism in fowl serum albumin—V. Protein synthesis in cell-free systems from regenerating liver of the fowl ( Gallus domesticus)

Abstract

1. 1. Removal of the left hepatic lobe from 2–6 week old chicks results in liver regeneration. 2. 2. Polyribosomes from regenerating livers contain fewer 80 S monomers than those from normal or sham-operated livers, but were as active in cell-free protein synthesis. 3. 3. High speed supernatant from regenerating liver stimulated amino acid incorporation more than preparations from sham-operated controls over wide ranges of time and supernatant, Mg 2+ and GTP concentrations. Supernatant activity was maximal (160% of control) 12–18 hr after partial hepatectomy. 4. 4. Neither the activity of amino acid activating enzymes nor ribonuclease differed sufficiently between regenerating and control liver preparations to explain the protein biosynthesis differences. 5. 5. The data were consistent with the hypothesis of a temporary increase in elongation factor activity following partial hepatectomy.