Streptococcal antitumor protein: expression in Escherichia coli cells and properties of the recombinant protein

Agric Biol Chem. 1991 Mar;55(3):743-50.


Streptococcal antitumor protein (SAGP) was produced by transformed E. coli JM103 carrying the SAGP gene downstream from the tac promoter. The purified recombinant SAGP had the same N-terminal amino acid sequence as that of the native SAGP isolated from Streptococcus pyogenes Su cells. Gel filtration analysis showed that the recombinant SAGP was a dimer, while the native SAGP was a tetramer. When the antitumor activity was tested against sarcoma 180 cells, the IC50 of the recombinant SAGP was 0.3 microgram/ml, about a quarter as active as the native SAGP. These results suggest that the quaternary structure of SAGP is important for the antitumor activity.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibiotics, Antineoplastic / chemistry*
  • Antibiotics, Antineoplastic / isolation & purification
  • Bacterial Proteins*
  • Base Sequence
  • Chromatography, High Pressure Liquid
  • Cloning, Molecular
  • DNA, Bacterial / chemistry
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Gene Expression Regulation, Bacterial*
  • Glycoproteins / biosynthesis
  • Glycoproteins / chemistry
  • Glycoproteins / genetics*
  • Molecular Sequence Data
  • Plasmids
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Sarcoma 180
  • Streptococcus pyogenes / genetics*
  • Streptococcus pyogenes / metabolism
  • Tumor Cells, Cultured


  • Antibiotics, Antineoplastic
  • Bacterial Proteins
  • DNA, Bacterial
  • Glycoproteins
  • Recombinant Proteins
  • SAGP protein, Streptococcus

Associated data

  • GENBANK/X55659