Incorporation of amino acids by a cell-free system prepared from human cells cultured in vitro

Abstract

1. A cell-free amino acid-polymerizing system has been prepared from human cells (EUE) cultured in vitro. The requirements and properties of the system are those expected for protein-synthesizing activity in vitro. 2. The system responds to endogenous mRNA, tobacco mosaic virus RNA and synthetic polynucleotides. 3. Of the compounds known to interfere with protein synthesis, pederin appears to be the most active, being inhibitory at concentrations as low as 0.01 μg/ml. 4. Ribosomes from EUE cells are active in the presence of polymerizing enzymes prepared from other organisms containing 80-S ribosomes but not from those endowed with 70-S ribosomes. Likewise, polymerizing enzymes from EUE cells are active only when added to 80-S ribosomes.