Characterization of the amino-terminal tryptic peptide of simian virus 40 small-t and large-T antigens

J Virol. 1978 Dec;28(3):992-6. doi: 10.1128/JVI.28.3.992-996.1978.


Simian virus 40 small-t and large-T antigen were synthesized in vitro and labeled with methionine donated by initiator tRNA. Tryptic peptide fingerprinting was used to identify the amino-terminal peptide of the two proteins. Similar fingerprint analysis of small-t and large-T made in vitro in the absence of acetyl coenzyme A showed that the mobility of the amino-terminal peptide was changed under these conditions and suggested that it is acetylated. These data establish that the amino-terminal methionine residue of simian virus 40 small-t and large-T results from an initiation event, not post-translational cleavage, and provides additional evidence that the amino terminus of both proteins is acetylated. The identification of the amino-terminal peptide provides a useful marker for further studies on different forms of T-antigen from cells infected with and transformed by simian virus 40 and related viruses.

MeSH terms

  • Acetylation
  • Antigens, Neoplasm / analysis*
  • Antigens, Viral / analysis*
  • Peptides / analysis
  • Simian virus 40 / analysis
  • Simian virus 40 / immunology*
  • Viral Proteins / analysis*
  • Viral Proteins / biosynthesis


  • Antigens, Neoplasm
  • Antigens, Viral
  • Peptides
  • Viral Proteins