Isolation and characterization of a novel perchloric acid-soluble protein inhibiting cell-free protein synthesis

J Biol Chem. 1995 Dec 15;270(50):30060-7. doi: 10.1074/jbc.270.50.30060.


We found a novel protein in the postmitochondria supernatant fraction of rat liver, which is soluble in 5% perchloric acid and strongly inhibits protein synthesis in a rabbit reticulocyte lysate system. The protein extracted from the supernatant fraction with 5% perchloric acid was purified by ammonium sulfate fractionation and CM-Sephadex chromatography. The protein was shown to consist of two identical subunits with a molecular mass of 14 kDa. By immunoscreening with the rabbit antisera against the protein, a cDNA encoding the protein was cloned and sequenced. The cDNA contained an open reading frame of 411 base pairs encoding a 136-amino acid protein with a molecular mass of 14,149 Da. The deduced amino acid sequence was completely identical with that constructed from all of the above peptides. Interestingly, the perchloric acid-soluble protein inhibited cell-free protein synthesis in the rabbit reticulocyte lysate system in a different manner from RNase A. The protein is likely to inhibit an initiation stage of cell-free protein synthesis. Among the rat tissues tested, the protein was located only in liver and kidney. These findings are the first report on a new inhibitor that may be involved in the regulation of protein synthesis in those tissues.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Cytosol / metabolism
  • Heat-Shock Proteins / biosynthesis
  • Heat-Shock Proteins / isolation & purification*
  • Heat-Shock Proteins / pharmacology
  • Liver / metabolism*
  • Male
  • Mass Spectrometry
  • Molecular Sequence Data
  • Open Reading Frames
  • Peptide Fragments / chemistry
  • Peptide Fragments / isolation & purification
  • Perchlorates
  • Protein Biosynthesis / drug effects*
  • Protein Synthesis Inhibitors / chemistry
  • Protein Synthesis Inhibitors / isolation & purification*
  • Protein Synthesis Inhibitors / pharmacology
  • Proteins / isolation & purification*
  • Proteins / pharmacology
  • Rabbits / immunology
  • Rats
  • Rats, Wistar
  • Reticulocytes / metabolism
  • Ribonucleases*
  • Sequence Homology, Amino Acid
  • Solubility


  • Heat-Shock Proteins
  • Peptide Fragments
  • Perchlorates
  • Protein Synthesis Inhibitors
  • Proteins
  • Rida protein, rat
  • Ribonucleases

Associated data

  • GENBANK/D49363