Partial purification and characterization of heat-stable enterotoxin produced by Yersinia enterocolitica

Keinosuke Okamoto, Takashi Inoue, Hidetaka Ichikawa, Yasuko Kawamoto, Akio Miyama

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


By using a suckling mouse assay, heat-stable enterotoxin (ST) was purified from the culture filtrate of Yersinia enterocolitica isolated from a diarrheal patient. The purification procedures involve ultrafiltration with an Amicon HIP-10 hollow fiber, ethanol fractionation, protamine sulfate treatment, diethylaminoethyl-Sephacel and hydroxylapatite column chromatographies, and Sephacryl S-200 superfine gel filtration. About 408-fold purification was achieved, with a yield of 12.0%. The minimal effective dose of purified ST was about 110 ng in the suckling mouse assay. The molecular weight of purified ST was 9,000 by Sephadex G-100 superfine gel filtration. The purified ST was stable to heating (100°C for 20 min, 121°C for 20 min) and did not lose its toxicity after treatment with protease, trypsin, lipase, phospholipase C, ribonuclease, deoxyribonuclease, β-glucosidase, and neuraminidase. The purified ST was separated by isoelectric focusing into two active fractions, with pI's of 3.29 (ST-1) and 3.00 (ST-2), respectively. Antiserum from guinea pigs immunized with the purified ST neutralized the activity of both Y. enterocolitica ST and Escherichia coli ST.

Original languageEnglish
Pages (from-to)554-559
Number of pages6
JournalUnknown Journal
Issue number2
Publication statusPublished - 1981
Externally publishedYes

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Infectious Diseases


Dive into the research topics of 'Partial purification and characterization of heat-stable enterotoxin produced by Yersinia enterocolitica'. Together they form a unique fingerprint.

Cite this