Shigella dysenteriae 1 cytotoxin: periplasmic protein releasable by polymyxin B and osmotic shock.

摘要: Treatment of Shigella dysenteriae 1 either with the antibiotic polymyxin B or by osmotic shock resulted in release 80 to 90% cytotoxin activity organism. Under conditions employed, toxin was accompanied appearance a periplasmic enzyme, 5'-nucleotidase. There no significant cytoplasmic contents, assessed measurement glucose-6-phosphate dehydrogenase activity. The and 5'-nucleotidase were both dependent on duration incubation with, concentration of, antibiotic. In terms specific (cytotoxin per milligram protein), extracts 20- 30-fold more active than crude preparation derived from whole-cell lysate. data strongly support location for Shiga utility extraction obtain starting material purification.