Isolation of an inhibitor of cell-free protein synthesis from Salmonella enteritidis.
Sonic extracts of Salmonella enteritidis, serotype enteritidis, contain a factor which inhibits eukaryotic cell-free protein synthesis tested on a rabbit reticulocyte lysate system and on a poly(U)-dependent system from Artemia salina embryos. The factor is heat-labile, does not diffuse through dialysis bags and is precipitated by ammonium sulphate. A 78% recovery of the factor was obtained in the 60-80 per cent ammonium sulphate saturation range, with a 3.3-fold purification. The factor binds to DEAE-cellulose. In the fraction eluted at 0.55 M NaCl, SDS-polyacrylamide gel electrophoresis shows only two protein bands (Mr 55,000 and 29,000). While the inhibitory activity on protein synthesis of the crude factor is fairly stable at 4 degrees C, it becomes very labile after DEAE-cellulose chromatography. The ID50 of the partially purified factor was less than 0.55 microgram (20-fold purification).
Dipartimento di Patologia sperimentale, Università di Bologna, Italy.
M
M
Brigotti
F
F
Rambelli
A
A
Nanetti
M
M
Zamboni
S
S
Sperti
L
L
Montanaro
D000645:Ammonium Sulfate; D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D002498:Centrifugation; D011232:Chemical Precipitation; D002848:Chromatography, DEAE-Cellulose; D003603:Cytotoxins / Q000302:isolation & purification* / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D014176:Protein Biosynthesis; D012477:Salmonella enteritidis
D001426:Bacterial Proteins; D003603:Cytotoxins; D000645:Ammonium Sulfate