A synthetic peptide substrate for initiation factor-2 kinases

Biochem Biophys Res Commun. 1991 Jul 31;178(2):430-7. doi: 10.1016/0006-291x(91)90125-q.


A peptide P(45-56) corresponding to residues 45-56 (sequence: ILLSELSRRRIR) of eIF-2 alpha was synthesised. It was phosphorylated by both of the well characterised eIF-2 alpha kinases viz.; the heme-controlled repressor (HCR) and the double stranded RNA-dependent inhibitor (dsI). Of four other protein kinases tested only protein kinase C (PKC) phosphorylated P(45-56), with complete dependence on phosphatidylserine. Only the residue corresponding to serine-51 in eIF-2 alpha was phosphorylated by HCR, dsI or PKC. The phosphorylation of the peptide by dsI and the phosphorylation of eIF-2 alpha by dsI or HCR showed sigmoidal kinetics with respect to substrate concentration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Kinetics
  • Molecular Sequence Data
  • Oligopeptides / chemical synthesis*
  • Oligopeptides / metabolism
  • Phosphopeptides / isolation & purification
  • Phosphorylation
  • Protein Kinases / metabolism*
  • Rabbits
  • Reticulocytes / enzymology
  • Substrate Specificity
  • eIF-2 Kinase


  • Oligopeptides
  • Phosphopeptides
  • Protein Kinases
  • eIF-2 Kinase