title: Purification and characterization of Escherichia coli heat-stable enterotoxin II.
abstract: Escherichia coli heat-stable enterotoxin II (STII) was purified to homogeneity by successive column chromatographies from the culture supernatant of a strain harboring the plasmid encoding the STII gene. The purified STII evoked a secretory response in the suckling mouse assay and ligated rat intestinal loop assay in the presence of protease inhibitor, but the response was not observed in the absence of the inhibitor. Analyses of the peptide by the Edman degradation method and fast atom bombardment mass spectrometry revealed that purified STII is composed of 48 amino acid residues and that its amino acid sequence was identical to the 48 carboxy-terminal amino acids of STII predicted from the DNA sequence (C. H. Lee, S. L. Mosely, H. W. Moon, S. C. Whipp, C. L. Gyles, and M. So, Infect. Immun. 42:264-268, 1983). STII has four cysteine residues which form two intramolecular disulfide bonds. Two disulfide bonds were determined to be formed between Cys-10-Cys-48 and Cys-21-Cys-36 by analyzing tryptic hydrolysates of STII.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujii
authors.forename: M
authors.initials: M
authors.lastname: Hayashi
authors.forename: S
authors.initials: S
authors.lastname: Hitotsubashi
authors.forename: Y
authors.initials: Y
authors.lastname: Fuke
authors.forename: H
authors.initials: H
authors.lastname: Yamanaka
authors.forename: K
authors.initials: K
authors.lastname: Okamoto
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001427:Bacterial Toxins / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007422:Intestines / Q000187:drug effects; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010957:Plasmids; D051381:Rats; D011919:Rats, Inbred Strains; D016339:Spectrometry, Mass, Fast Atom Bombardment; D014357:Trypsin
chemical_list: D000596:Amino Acids; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli); D014357:Trypsin