Amino acid sequence of heat‐stable enterotoxin produced by Vibrio cholerae non‐01

Abstract

The amino acid sequence of heat-stable enterotoxin, produced by Vibrio cholerae non-01 and isolated from its culture su~rnatant, was determined by both Edman degradation of native and reductively carboxymethylated enterotoxin and also a combination of fast atom bombardment mass spectrometry and carboxypeptidase Y digestion of native enterotoxin to be as follows: Ile-Asp-Cys-Cys-Glu-Ile-Cys-Cys-Asn-ProAla-Cys-Phe-Gly-Cys-Leu-Asn.This sequence is very similar, but not identical, to those of heat-stable enterotoxins produced by enterotoxigenic Escherichia coli and Yersinia enterocolitica. (Vibrio cholerae non-01)heat-stability Enterotoxin Primary str~eture

Uroguanylin: structure and activity of a second endogenous peptide that stimulates intestinal guanylate cyclase.

“…Since the final purification of uroguanylin required C8 microbore RP-HPLC to provide homogenous peaks of UVabsorbing peptides and all of the purified peptides were used in the analyses, a peptide was synthesized corresponding to the linear sequence EDCELCINVACTGC [uroguanylin- (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)] to test its potency and efficacy when T84 cells are used as a model bioassay. Sequential oxidation methods were used to provide disulfide bonds from Cys-3 to Cys-11 and Cys-6 to 4.…”

“…Enteric bacteria, including Escherichia coli, Yersinia enterocolitica, and Vibrio cholerae, cause diarrhea by secreting small heat-stable enterotoxins (STs) that bind to and activate an intestinal isoform of membrane guanylate cyclase (2)(3)(4). Guanosine 3',5'-cyclic monophosphate (cGMP) is the second messenger molecule that mediates the parallel stimulation of Cl-secretion and inhibition of Na+ absorption elicited by STs (5,6).…”

Mode of disulfide bond formation of a heat‐stable enterotoxin (STh) produced by a human strain of enterotoxigenic Escherichia coli

“…The full enterotoxigenic activity of STI has been found to be expressed by a segment with 13 amino acid residues, which includes 6 halfcystines [10]. Recently, STI-like enterotoxins from Yersinia enterocolitica [11,12], Vibrio cholerae non-01 [13], and V. mimicus (unpublished) have been isolated and sequenced ( fig.l). These enterotoxins have common regions with 13 amino acid residues including 6 Cys residues, which are located in the same relative positions and linked intramolecularly by three disulfide bonds.…”

“…The enterotoxins of Y. enterocolitica and V. cholerae non-01 have similar biological and physicochemical properties to those of STI of E. coil, suggesting that these enterotoxins have the same disulfide bonds and therefore similar tertiary structures. Amino acid sequences of heat-stable enterotoxins produced by enteric bacteria: a, see [7]; b, see [8,9]; c, see I1 l, 12]; d, see [13]; e, unpublished. The single letter notations used are cited from [14].…”

Genetic fusion of a non‐toxic heat‐stable enterotoxin‐related decapeptide antigen to cholera toxin B‐subunit

“…The cysteine residues are contained within a 15 amino acid stretch of the protein and this region is not only identical between the two different variants of STa molecules known (STa I and STa II) but it also shares extensive homology with the heat-stable enterotoxins from non-01 V. cholerae and Yersinia enterocolitica [20,21]. The multiple disulfide bridges in STa have been implicated in its toxicity [22] and they have thus become targets for manipulations with the aim to obtain safe vaccine candidates.…”