Abstract
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
Substances
-
Antibiotics, Antineoplastic
-
Bacterial Proteins
-
DNA, Bacterial
-
Glycoproteins
-
Recombinant Proteins
-
SAGP protein, Streptococcus