Purification and sequence determination of heat-stable enterotoxin elaborated by a cholera toxin-producing strain of Vibrio cholerae O1.
Four molecular species of heat-stable enterotoxins elaborated by a cholera toxin-producing strain of Vibrio cholerae O1 were isolated from its culture supernatant. The amino acid sequence of one of the enterotoxins was determined to be Phe-Ile-Lys-Gln-Val-Asp-Glu-Asn-Gly-Asn-Leu-Ile-Asp-Cys-Cys-Glu-Ile-Cys- Cys-Asn-Pro-Ala-Cys-Phe-Gly-Cys-Leu-Asn with three intramolecular disulfide linkages. The other enterotoxins had shorter amino acid sequences in the N-terminal regions, but possessed the same sequence in their C-terminal regions including the three disulfide linkages. The enterotoxins with the shorter N-terminal sequences showed more potent toxicities, and the minimum effective dose of the longest one with 28 amino acid residues was 10-folds of that of the shortest one.
Yoshino
K
K
Institute for Protein Research, Osaka University, Japan.
Miyachi
M
M
Takao
T
T
Bag
P K
PK
Huang
X
X
Nair
G B
GB
Takeda
T
T
Shimonishi
Y
Y
D000595:Amino Acid Sequence; D002772:Cholera Toxin / Q000096:biosynthesis; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D004768:Enterotoxins / Q000737:chemistry* / Q000302:isolation & purification*; D006358:Hot Temperature; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism; D017421:Sequence Analysis; D012697:Serine Endopeptidases / Q000378:metabolism; D014734:Vibrio cholerae / Q000378:metabolism*
D004768:Enterotoxins; D010446:Peptide Fragments; D002772:Cholera Toxin; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase