Inhibitory effect of alpha-fetoprotein on protein synthesis in a reticulocyte lysate cell-free system.
The inhibitory effect of human alpha-fetoprotein on the protein synthesis (incorporation of [3H]leucine into the total protein fraction) weas observed in a rabbit reticulocyte lysate cell-free system. The incorporation was inhibited to 50% of the control level by 14-16 microM alpha-fetoprotein, and decreased to about 15% at a concentration higher than 40 microM. An almost identical dose dependence was obtained between fetal alpha-fetoprotein and hepatoma-derived alpha-fetoprotein. This inhibitory effect on the protein synthesis was due to the interference of alpha-fetoprotein to the 40 S initiation complex formation from the ternary complex (eukaryotic initiation factor 2.GTP.Met-tRNAfMet). In contrast human serum albumin purified from fetal cord sera did not exhibit this inhibition under the same conditions. These results indicate that alpha-fetoprotein may function as a regulator of the protein synthesis in the fetal stage.
D006528:Carcinoma, Hepatocellular / Q000032:analysis*; D002474:Cell-Free System / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005312:Fetal Blood / Q000032:analysis*; D006801:Humans; D007930:Leucine / Q000378:metabolism; D008113:Liver Neoplasms; D010448:Peptide Initiation Factors / Q000037:antagonists & inhibitors; D014176:Protein Biosynthesis; D012156:Reticulocytes / Q000378:metabolism; D012709:Serum Albumin / Q000494:pharmacology; D000509:alpha-Fetoproteins / Q000494:pharmacology*
D010448:Peptide Initiation Factors; D012709:Serum Albumin; D000509:alpha-Fetoproteins; D007930:Leucine