title: Translational inhibition by heme of the synthesis of hepatic delta-aminolevulinate synthase in a cell-free system.
abstract: Synthesis of delta-aminolevulinate synthase in a rabbit reticulocyte lysate system directed by total polysomes from the liver of allylisopropylacetamide-treated rats was studied with the combined use of [3H]leucine and a specific rabbit antibody. The protein synthesis observed in the cell-free system employed represented mainly the peptide chain elongation and its termination rather than the net synthesis involving initiation. Synthesis of delta-aminolevulinate synthase in this cell-free system was inhibited progressively with the increased addition of hemin; the synthesis was reduced to about 40% by about 30 microM hemin. Synthesis of total protein, however, was not significantly affected by the addition of hemin. The data obtained suggest that heme inhibits a peptide chain elongation step in the synthesis of delta-aminolevulinate synthase.
mesh_terms: D000624:5-Aminolevulinate Synthetase / Q000235:genetics*; D000502:Allylisopropylacetamide / Q000494:pharmacology; D000818:Animals; D002474:Cell-Free System; D006418:Heme / Q000494:pharmacology*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D011132:Polyribosomes / Q000187:drug effects / Q000201:enzymology*; D014176:Protein Biosynthesis / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000502:Allylisopropylacetamide; D006418:Heme; D000624:5-Aminolevulinate Synthetase